U.S. patent application number 11/639334 was filed with the patent office on 2007-04-19 for semiconductor memory element and lifetime operation starting appartus therefor.
This patent application is currently assigned to Pioneer Corporation. Invention is credited to Kazuo Kuroda, Shuuichi Yanagisawa.
Application Number | 20070085078 11/639334 |
Document ID | / |
Family ID | 29706561 |
Filed Date | 2007-04-19 |
United States Patent
Application |
20070085078 |
Kind Code |
A1 |
Kuroda; Kazuo ; et
al. |
April 19, 2007 |
Semiconductor memory element and lifetime operation starting
appartus therefor
Abstract
An example memory includes an address control portion, a
protection film, a property deterioration material layer, data
storage areas, and bonding pads. The protection film protects an
organic semiconductor layer of a semiconductor circuit and prevents
intrusion of moisture or chemical molecules in the air, light, or
the like, into the organic semiconductor layer. Deterioration of
the organic semiconductor layer is started by breaking the
protection film and using a specified means, thus starting
operation of the lifetime period. The property deterioration
material layer contains a material for deteriorating the property
of the organic semiconductor and deterioration of the organic
semiconductor layer is started, for example, by diffusing the
material into the organic semiconductor layer.
Inventors: |
Kuroda; Kazuo; (Saitama,
JP) ; Yanagisawa; Shuuichi; (Saitama, JP) |
Correspondence
Address: |
NIXON & VANDERHYE, PC
901 NORTH GLEBE ROAD, 11TH FLOOR
ARLINGTON
VA
22203
US
|
Assignee: |
Pioneer Corporation
|
Family ID: |
29706561 |
Appl. No.: |
11/639334 |
Filed: |
December 15, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10516336 |
Apr 13, 2005 |
|
|
|
PCT/JP03/06209 |
May 19, 2003 |
|
|
|
11639334 |
Dec 15, 2006 |
|
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|
Current U.S.
Class: |
257/40 ;
257/E51.005 |
Current CPC
Class: |
H01L 27/283 20130101;
H01L 27/28 20130101; H01L 51/107 20130101; H01L 2924/12044
20130101; H01L 23/573 20130101; G11C 29/50 20130101; H01L 2924/0002
20130101; H01L 23/585 20130101; Y10S 257/922 20130101; H01L
2924/0002 20130101; H01L 2924/00 20130101 |
Class at
Publication: |
257/040 ;
257/E51.005 |
International
Class: |
H01L 29/08 20060101
H01L029/08 |
Foreign Application Data
Date |
Code |
Application Number |
May 31, 2002 |
JP |
2002-160769 |
Claims
1. A memory device comprising: memory elements for storing data,
the memory elements comprising circuit portions including an
organic semiconductor material; and means for causing deterioration
over time of the organic semiconductor material to thereby
determine a time period during which data stored in the memory
elements can be reproduced, wherein the deterioration-causing means
is arranged so that the deterioration caused thereby can begin at a
specified time after fabrication of the memory device.
2. The memory device according to claim 1, wherein the memory
elements are organized into two or more storage areas and the
deterioration-causing means is provided separately for each storage
area, whereby data stored in memory cells in different storage
areas can be reproduced for different time periods.
3. The memory device according to claim 1, wherein the memory
device is embodied as a memory card.
4. A memory device comprising: memory elements for storing data,
the memory elements comprising circuit portions including an
organic semiconductor material; and a deterioration-causing
arrangement that causes deterioration over time of the organic
semiconductor material to thereby determine a time period during
which data stored in the memory elements can be reproduced, wherein
the deterioration-causing arrangement is arranged so that the
deterioration caused thereby can begin at a specified time after
fabrication of the memory device.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of application Ser. No.
10/516,336, filed Apr. 13, 2005, which is the national stage of
international Application No. PCT/JP03/06209 filed May 19, 2003,
which designated the United States and claims the benefit of JP
2002-160769, filed May 31, 2002.
TECHNICAL FIELD
[0002] The present invention relates to a semiconductor memory
element using an organic semiconductor having a predetermined
lifetime for defining a retention time during which recorded data
can be reproduced and capable of starting the lifetime at a
predetermined time, and further relates to a lifetime operation
starting apparatus therefor.
BACKGROUND ART
[0003] High density and high integration semiconductor devices have
been manufactured and supplied, owing to a development of fine
technology in a semiconductor manufacturing. Particularly in a
semiconductor memory manufactured in a sub micron rule, a great
number of memory elements are formed in one chip, which allows
recording music and video for a long time, coupled with a lowered
bit unit price and with a development in data compressing
technology. Furthermore, employing an organic semiconductor element
with a lower price may make the bit unit price lower.
[0004] In the semiconductor memory useful as a record medium, as
well as in view of the cost, it is expected to prevent or block the
data reading after a predetermined time elapse from the data
recording, for example in an application for a commuter pass
(ticket), or an application in a rental business of music or video
soft and the like.
[0005] As the semiconductor memory compatible to such an
expectation, Japanese Patent Application Laid-Open No. H10-189780
discloses an example of the technology. According to this, a gate
insulation layer may be formed of a first layer of a silicon
dioxide film, a second layer of a silicon nitride film and a third
layer of a silicon dioxide film, in which a composition rate of Si
atom and N atom in the second layer of the silicon nitride film is
set to a value corresponding to a desired data effective time.
Owing to this construction, the data effective time is expected to
be set in such a manner that a shallow electric charge lap is
positively formed to deteriorate the memory retention, and an
amount of the electric charge to be accumulated in an electric
charge accumulation mechanism is reduced and thereby the lifetime
of the data retention is shortened. The lifetime of record data in
this type of memory is determined by controlling the composition
rate of Si atom and N atom in the silicon nitride during the chip
fabrication.
DISCLOSURE OF INVENTION
[0006] However, in the aforementioned memory in which the lifetime
of the record data is determined by controlling the composition
rate of Si atom to N atom, the memory lifetime is adversely
determined on the fabrication. The lifetime is based on the
fabrication time, and it is difficult to know, on an actual data
recording, an elapsed time from the fabrication. Therefore, it is
not possible to know the effective time from the data recording,
which is a problem in a practical use.
[0007] Therefore, it is an object of the present invention to
provide a semiconductor memory element and a lifetime operation
starting apparatus therefor suitable for a mass production with a
lower cost, capable of setting the lifetime of the recorded data,
i.e. the reproducible effective time and capable of desirably
setting a start of the operation within the lifetime.
[0008] The first semiconductor memory element of the present
invention in order to solve the above problems is a semiconductor
memory element comprising: a substrate; a semiconductor circuit
portion made of an organic semiconductor disposed on the substrate;
and a protection portion disposed adjacent to the semiconductor
circuit portion, the protection portion being made of a material
capable of causing a crack extending to the semiconductor circuit
portion due to a predetermined means.
[0009] According to the first semiconductor memory element of the
present invention, the semiconductor circuit is made of the organic
semiconductor, and the protection portion for protecting a layer
forming the semiconductor circuit is disposed. The protection
portion can make a crack reachable to the layer forming the
semiconductor circuit by the predetermined means. From the crack,
moisture or oxygen in the air penetrates into the semiconductor
circuit portion and diffuses therein. The organic semiconductor is
deteriorated in its performance by the moisture or oxygen. And the
organic semiconductor fails to function after a certain time
period. Therefore, it becomes impossible to reproduce the recorded
data after a certain time period, and thereby the memory and the
like having the predetermined lifetime (the "lifetime" in the
present invention means a time period from a start time of the
deterioration in the organic semiconductor by the performance
deterioration material until the organic semiconductor loses the
semiconductor function.) is formed. Furthermore, the lifetime can
be set depending on the extent of cracks to be caused.
[0010] The second semiconductor memory element of the present
invention in order to solve the above problems is a semiconductor
memory element comprising: a substrate; a semiconductor circuit
portion made of an organic semiconductor disposed on the substrate;
a protection portion disposed adjacent to the semiconductor circuit
portion and having a window portion; and a freely strippable seal
member for sealing the window portion of the protection
portion.
[0011] According to the second semiconductor memory element of the
present invention, the semiconductor circuit is made of the organic
semiconductor, and the protection portion for protecting a layer
forming the semiconductor circuit is disposed. The protection
portion has a window portion, which is sealed with the seal member.
If the seal member is stripped off, moisture or oxygen in the air
penetrates into the semiconductor circuit and diffuses therein.
From then, the organic semiconductor is deteriorated in its
performance by the moisture or oxygen. And the organic
semiconductor fails to function after a certain time period.
Therefore, the memory and the like having the predetermined
lifetime are formed.
[0012] The third semiconductor memory element of the present
invention in order to solve the above problems is a semiconductor
memory element comprising: a substrate; a semiconductor circuit
portion made of an organic semiconductor disposed on the substrate;
a protection portion disposed adjacent to the semiconductor circuit
portion; and a performance deterioration material layer including a
performance deterioration material and disposed adjacent to the
protection portion, the protection portion being made of a material
capable of causing a crack extending to the semiconductor circuit
portion due to a predetermined means.
[0013] According to the third semiconductor memory element of the
present invention, the semiconductor circuit is made of the organic
semiconductor, and the protection portion for protecting a layer
forming the semiconductor circuit is disposed. Furthermore, the
performance deterioration material layer including the performance
deterioration material for deteriorating the organic semiconductor
material is disposed above the protection portion. The protection
portion can make a crack reachable to the layer forming the
semiconductor circuit by the predetermined means. From the crack,
the performance deterioration material in the performance
deterioration material layer penetrates into the semiconductor
circuit portion and diffuses therein. The organic semiconductor is
deteriorated in its performance by the performance deterioration
material. And the organic semiconductor fails to function after a
certain time period. Therefore, the memory and the like having the
predetermined lifetime to make the recorded data reproduction
impossible after a certain time period is formed. Furthermore, the
lifetime can be set depending on the extent of cracks to be
caused.
[0014] In an aspect of the first or third semiconductor memory
element of the present invention, the predetermined means is a
mechanical punch means.
[0015] According to this aspect, a micro-hole/micro-holes is/are
formed in the protection portion by a mechanical means such as a
needle like means. The moisture or oxygen in the air, or the
performance deterioration material in the performance deterioration
material layer can penetrate into the semiconductor circuit portion
and diffuse therein.
[0016] In another aspect of the first or third semiconductor memory
element of the present invention, the predetermined means is a
heating means.
[0017] According to this aspect, the crack is caused by heating the
protection portion. The moisture or oxygen in the air, or the
performance deterioration material in the performance deterioration
material layer can penetrate into the semiconductor circuit portion
and diffuse therein.
[0018] In another aspect of the first or third semiconductor memory
element of the present invention, the predetermined means is a
pressurizing means.
[0019] According to this aspect, the crack is caused by
pressurizing the protection portion. The moisture or oxygen in the
air, or the performance deterioration material in the performance
deterioration material layer can penetrate into the semiconductor
circuit portion and diffuse therein.
[0020] In another aspect of the semiconductor memory element of the
present invention, the predetermined means is a light irradiation
means.
[0021] According to this aspect, the crack is caused by irradiating
light of a predetermined wavelength to the protection portion. The
moisture or oxygen in the air, or the performance deterioration
material in the performance deterioration material layer can
penetrate into the semiconductor circuit portion and diffuse
therein.
[0022] The fourth semiconductor memory element of the present
invention in order to solve the above problems is a semiconductor
memory element comprising: a substrate; a semiconductor circuit
portion disposed on the substrate and made of an organic
semiconductor including a performance deterioration material; and a
protection portion disposed adjacent to the semiconductor circuit
portion, wherein the performance deterioration material is
activated by a predetermined means.
[0023] According to the fourth semiconductor memory element of the
present invention, the semiconductor circuit is made of the organic
semiconductor, and the protection portion for protecting a layer
forming the semiconductor circuit is disposed. The performance
deterioration material for deteriorating the organic semiconductor
performance is dispersed in the semiconductor circuit portion. The
deterioration material is activated by releasing the trigger
("releasing the trigger" in the present application means to start
the activation of the performance deterioration material), which
causes the deterioration of the organic semiconductor. And the
organic semiconductor fails to function after a certain time
period. Therefore, the memory and the like having the predetermined
lifetime to make the recorded data reproduction impossible after a
certain time period is formed. Furthermore, the lifetime can be set
depending on the extent of the performance deterioration material
dispersion or the extent of the activation.
[0024] The fifth semiconductor memory element of the present
invention in order to solve the above problems is a semiconductor
memory element comprising: a substrate; a semiconductor circuit
portion disposed on the substrate and made of an organic
semiconductor including a performance deterioration material; and a
film disposed adjacent to the semiconductor circuit portion,
capable of obtaining light transmissive property due to an
irradiation of light having a predetermined wavelength thereon,
wherein the performance deterioration material is activated by a
predetermined means.
[0025] According to the fifth semiconductor memory element of the
present invention, the semiconductor circuit is made of the organic
semiconductor, and the color film layer is disposed above a layer
forming the semiconductor circuit to cover and protect the latter.
The performance deterioration material for deteriorating the
organic semiconductor is dispersed in the semiconductor circuit
portion. The color film obtains light transmissive property by
irradiating the light of the predetermined wavelength. Then, the
performance deterioration material is activated by the released
trigger, and thereby the organic semiconductor is deteriorated, and
the organic semiconductor fails to function after a certain time
period. Therefore, the memory and the like having the predetermined
lifetime to make the recorded data reproduction impossible after a
certain time period is formed. Furthermore, the lifetime can be set
depending on the extent of the performance deterioration material
dispersion or the extent of the activation.
[0026] The sixth semiconductor memory element of the present
invention in order to solve the above problems is a semiconductor
memory element comprising: a substrate; a semiconductor circuit
portion disposed on the substrate and made of an organic
semiconductor including a performance deterioration material; a
protection portion disposed adjacent to the semiconductor circuit
portion and having a window portion; and a freely strippable seal
member for sealing the window portion of the protection
portion.
[0027] According to the sixth semiconductor memory element of the
present invention, the semiconductor circuit is made of the organic
semiconductor, and the protection portion is disposed above a layer
forming the semiconductor circuit. The performance deterioration
material for deteriorating the organic semiconductor is dispersed
in the semiconductor circuit portion. The protection portion is
provided with the window portion at a position corresponding to the
semiconductor circuit. The window portion is sealed with the seal
member. If the seal member is stripped off to release the trigger
for activating the performance deterioration material dispersed in
the semiconductor circuit portion by the predetermined means, the
organic semiconductor is deteriorated. And the organic
semiconductor fails to function after a certain time period.
Therefore, the memory and the like having the predetermined
lifetime to make the recorded data reproduction impossible after a
certain time period is formed. Furthermore, the lifetime can be set
depending on the extent of the performance deterioration material
dispersion or the extent of the activation.
[0028] In an aspect of the semiconductor memory element of the
present invention, the performance deterioration material is
encapsulated.
[0029] According to this aspect, some performance deterioration
materials begin to deteriorate from the beginning of the
dispersion. However, if these performance deterioration materials
are encapsulated and the capsule is broken on the time to begin the
deterioration, the organic semiconductor starts to deteriorate.
[0030] In another aspect of the semiconductor memory element of the
present invention, the predetermined means is a pressurizing
means.
[0031] According to this aspect, the performance deterioration
material dispersed in the semiconductor circuit portion made of the
organic semiconductor is activated by pressurizing.
[0032] In another aspect of the semiconductor memory element of the
present invention, the predetermined means is a heating means.
[0033] According to this aspect, the performance deterioration
material dispersed in the semiconductor circuit portion made of the
organic semiconductor is activated by heating.
[0034] In another aspect of the semiconductor memory element of the
present invention, the predetermined means is an UV irradiation
means.
[0035] According to this aspect, the performance deterioration
material dispersed in the semiconductor circuit portion made of the
organic semiconductor is activated by irradiating UV (ultraviolet)
rays.
[0036] In another aspect of the semiconductor memory element of the
present invention, the predetermined means is an electron beam
irradiation means.
[0037] According to this aspect, the performance deterioration
material dispersed in the semiconductor circuit portion made of the
organic semiconductor is activated by irradiating electron
beam.
[0038] In another aspect of the semiconductor memory element of the
present invention, the deterioration in the semiconductor circuit
portion of the organic semiconductor is started by stripping off
the seal member.
[0039] According to this aspect, in the case that the protection
portion provided with the window portion corresponding to a
predetermined circuit position of the semiconductor circuit portion
is provided, if the seal member sealing the window portion is
stripped off, the organic semiconductor starts to deteriorate.
[0040] In another aspect of the semiconductor memory element of the
present invention, the semiconductor portion is a semiconductor
portion in a range corresponding to a predetermined circuit portion
of the semiconductor circuit portion.
[0041] According to this aspect, in the semiconductor circuit
portion to be deteriorated, the organic semiconductor can be
deteriorated relative to an arbitrary part. Therefore, there is no
need of the configuration to deteriorate the organic semiconductor
relative to the entire circuit.
[0042] In another aspect of the semiconductor memory element of the
present invention, the predetermined circuit portion is a data
area.
[0043] According to this aspect, the lifetime is determined by
deteriorating the data area of the semiconductor circuit.
[0044] In another aspect of the semiconductor memory element of the
present invention, the predetermined circuit portion is a
management information area.
[0045] According to this aspect, the lifetime is determined by
deteriorating the management information area of the semiconductor
circuit.
[0046] In another aspect of the semiconductor memory element of the
present invention, the predetermined circuit portion is an electric
power shutdown switch.
[0047] According to this aspect, the lifetime is determined by
deteriorating the electric power source shut down switch of the
semiconductor circuit.
[0048] In another aspect of the semiconductor memory element of the
present invention, the predetermined circuit portion is an
encryption key record area.
[0049] According to this aspect, the lifetime is determined by
deteriorating the encryption key record area of the semiconductor
circuit.
[0050] The first lifetime operation starting apparatus for the
semiconductor memory element of the present invention in order to
solve the above problems is a lifetime operation starting apparatus
having an starting device for starting an operation of a
semiconductor memory element using an organic semiconductor within
a lifetime, comprising a seal strip off device for stripping off a
seal attached to a position corresponding to a predetermined
portion of the organic semiconductor in order to deteriorate a
performance of the organic semiconductor as the starting
device.
[0051] According to the first lifetime operation starting apparatus
for the semiconductor memory element of the present invention, in
the case that the protection portion covering the organic
semiconductor is provided with the window portion, which is sealed
with the seal member, the trigger to start the lifetime is
stripping off the seal member. Therefore, the lifetime operation
starting apparatus is provided with the seal strip off device for
stripping off the seal member. A mechanism may be additionally
employed in order to strip off the seal automatically, when the
semiconductor memory element is mounted onto the record apparatus
for the data recording.
[0052] The second lifetime operation starting apparatus for the
semiconductor memory element of the present invention, a lifetime
operation starting apparatus having an starting device for starting
an operation of a semiconductor memory element using an organic
semiconductor within a lifetime, comprising, in order to cause a
crack in a protection portion protecting the organic semiconductor
as the starting device, at least one of a mechanical punch device
for punching a microhole through the protection portion; a heating
device for heating the protection portion; a pressurizing device
for pressurizing the protection portion; and a light irradiation
device for irradiating the protection portion with light.
[0053] According to the second lifetime operation starting
apparatus for the semiconductor memory element of the present
invention, there is provided with any one or a plurality of a
mechanism for mechanically forming a mirco-hole/micro-holes, a
mechanism for causing the crack by heating, a mechanism for causing
the crack by pressurizing and a mechanism for causing the crack by
irradiation with light, as a device for causing the crack in the
protection portion protecting the organic semiconductor and
releasing the trigger to the deterioration of the organic
semiconductor. It may be employed depending on the formation of the
protection portion and the formation of the performance
deterioration material. Alternatively, the deterioration speed of
the organic semiconductor can be controlled to determine the
lifetime by employing a mechanism for controlling the operation
time. Furthermore, these mechanisms can be additionally disposed at
the record apparatus for the semiconductor memory element, in order
to release the trigger on the data recording.
[0054] The third lifetime operation starting apparatus for the
semiconductor memory element of the present invention in order to
solve the above problems is a lifetime operation starting apparatus
having an starting device for starting an operation of a
semiconductor memory element using an organic semiconductor within
a lifetime, comprising, in order to activate a performance
deterioration material dispersed in the organic semiconductor as
the starting device, at least one of: a UV irradiation device for
irradiating the performance deterioration material in the organic
semiconductor with UV rays; and an electron beam irradiation device
for irradiating the performance deterioration material in the
organic semiconductor with electron beam.
[0055] According to the third lifetime operation starting apparatus
for the semiconductor memory element of the present invention,
there is provided with any one or a plurality of a mechanism for
irradiating the UV rays to the performance deterioration material
and a mechanism for irradiating the electron beam to the
performance deterioration material, in order to activate the
performance deterioration material dispersed in the organic
semiconductor. It may be employed depending on the formation of the
protection portion and the formation of the performance
deterioration material. Furthermore, the deterioration speed of the
organic semiconductor can be controlled to determine the lifetime
by employing a mechanism for controlling the operation time.
Furthermore, these mechanisms can be additionally disposed at the
record apparatus for the semiconductor memory element to release
the trigger on the data recording.
[0056] These effects and other advantages of the present invention
will be apparent from the following explanation.
BRIEF DESCRIPTION OF DRAWINGS
[0057] FIG. 1 is a general view illustrating a construction of the
semiconductor memory element of the present invention.
[0058] FIG. 2 is a general view illustrating another construction
of the semiconductor memory element of the present invention.
[0059] FIG. 3 is a general view illustrating a conventional
semiconductor memory element.
[0060] FIG. 4 is a view illustrating the first element construction
of the semiconductor memory element of the present invention.
[0061] FIG. 5 is a view illustrating the second element
construction of the semiconductor memory element of the present
invention.
[0062] FIG. 6 is a view illustrating an element construction of the
conventional semiconductor memory element.
[0063] FIG. 7(A) and FIG. 7.(B) are views illustrating the first
example of the semiconductor memory element according to the
present invention.
[0064] FIG. 8(A) and FIG. 8.(B) are views illustrating the second
example of the semiconductor memory element according to the
present invention.
[0065] FIG. 9(A) and FIG. 9.(B) are views illustrating the third
example of the semiconductor memory element according to the
present invention.
[0066] FIG. 10(A) and FIG. 10.(B) are views illustrating the fourth
example of the semiconductor memory element according to the
present invention.
[0067] FIG. 11(A) and FIG. 11.(B) are views illustrating the fifth
example of the semiconductor memory element according to the
present invention.
[0068] FIG. 12(A) and FIG. 12.(B) are views illustrating the sixth
example of the semiconductor memory element according to the
present invention.
[0069] FIG. 13 is a view illustrating the first example of a card
like semiconductor memory element of the present invention.
[0070] FIG. 14 is a view illustrating the second example of a card
like semiconductor memory element of the present invention.
[0071] FIG. 15 is a view illustrating the third example of a card
like semiconductor memory element of the present invention.
[0072] FIG. 16 is a view illustrating an exemplary construction of
the lifetime operation starting apparatus for the card like
semiconductor memory element of the present invention.
BEST MODE FOR CARRYING OUT THE INVENTION
[0073] The semiconductor memory element according to the present
invention is a memory using the organic semiconductor to construct
the circuit, allowing the recorded data reading for a certain time
period (referred to as the "lifetime" herein as appropriate) during
which the memory function is maintained, although the deterioration
trigger is released, owing to the organic semiconductor
characteristic property, for example the property of the
deterioration because of chemical reactions with the moisture or
oxygen, or the predetermined chemicals. The lifetime of the memory
can be activated at any time, and the lifetime length can be set
depending on the conditions.
[0074] Thus, it is a memory capable of setting the reproducible
time length of the recorded data and making the data reproduction
impossible after the elapse of the set time length, for example
suitable for a commuter pass (ticket) with the expiration date
fixed, the rental business of the music or video soft and so on.
Furthermore, since the organic material is employed, the element
can be in a large size by using a printing technology, and the cost
is small.
[0075] Incidentally, the form to make the data reproduction
impossible is not limited to delete the recorded data itself, but
includes breaking the management information or the encryption key
to make a state that the recorded data cannot be reproduced.
[0076] First, the construction of the semiconductor memory element
of the present invention will be explained, with reference to FIG.
1 to FIG. 6. FIG. 1 illustrates an outline of a semiconductor
memory element construction according to the present invention.
FIG. 2 illustrates an outline of another semiconductor memory
element construction according to the present invention. FIG. 3
illustrates an outline of a conventional semiconductor memory
element for a comparison. Furthermore, FIG. 4 illustrates the first
element configuration of the semiconductor memory element according
to the present invention, and FIG. 5 illustrates the second element
configuration. FIG. 6 illustrates a conventional element
configuration for a comparison.
[0077] The memory 1 of the semiconductor memory element according
to the present invention, as shown in FIG. 1, is provided with an
address control portion 10; a protection film 11; a performance
deterioration material layer 12; data storage areas 14, 15, 16, 17;
and a bonding pad 18.
[0078] The address control portion 10 designates storage positions
in the data storage areas 14, 15, 16 and 17, on the basis of the
addresses of rows and columns inputted from the external
terminal.
[0079] The protection film 11 is formed to protect the organic
semiconductor layer constructing the semiconductor circuit, and
prevents the moisture in the air, the chemicals, the light or the
like from penetrating into the organic semiconductor layer. On the
other hand, if this protection film 11 is destroyed and the
predetermined means are performed, the organic semiconductor layer
starts to deteriorate and enters the lifetime length operation.
[0080] The performance deterioration material layer 12 includes the
material for deteriorating the organic semiconductor performance.
If this material diffuses within the organic semiconductor layer,
the organic semiconductor layer is deteriorated to determine the
lifetime. Before the diffusion, the protection film 11 prevents the
material from contacting with the organic semiconductor layer. As
mentioned above, if this protection film 11 is destroyed, the
performance deterioration material diffuses within the organic
semiconductor layer.
[0081] Incidentally, a method or configuration for deteriorating
the organic semiconductor layer is not limited to this example, and
various forms will be explained in detail later.
[0082] The data storage areas 14, 15, 16 and 17 are areas for
storing data. The data effective time can be set for each area. It
will be obvious to those skilled in the art that the data storage
areas may be a united single area, or may be further divided into
more areas. Furthermore, the protection film 11 may be disposed
separately and individually for each data storage area. Thereby, it
is possible to set individual lifetimes for each data storage
area.
[0083] The bonding pad 18 is a connecting terminal for establishing
an electrical connection with the external circuit. There are
provided with terminals corresponding to an electric power source,
a data I/O (input/output), a data address, a record reproduction
signal and other control signals of the memory 1.
[0084] Next, the memory 2 of the semiconductor memory element
according to the present invention, as shown in FIG. 2, is provided
with an address control portion 10; a protection film 11; a
performance deterioration material layer 12; a power supply switch
13; data storage areas 14, 15, 16; a bonding pad 18; an encryption
key storage area 19; and an encryption circuit 20.
[0085] Here, the constructions and operations of the address
control portion 10, the protection film 11, the performance
deterioration material layer 12, the data storage areas 14, 15, 16
and the bonding pad 18 are the same as those of the aforementioned
memory 1, and thus the same explanation is not repeated.
[0086] The memory 2 is provided with the device for encrypting the
data to be recorded, the device for storing the encryption key, and
the switch for controlling the power supply respectively to each
data storage area and the encryption key storage area. The data
reproduction operation within the lifetime can be set by
deteriorating the organic semiconductor forming the encryption key
storage area 19 and the power supply switch 13.
[0087] The power supply switch 13 may be individually provided for
each data storage area 14, 15 or 16, and the encryption key storage
area 19. The protection film 11 is provided above these power
supply switches 13, and the performance deterioration material
layer 12 is further provided adjacent to the protection film 11, if
the protection film 11 above the power supply switch 13
corresponding to a desired area is destroyed, the performance
deterioration material in the performance deterioration material
layer 12 diffuses within the organic semiconductor forming the
desired power supply switch 13, so that the operation of the power
supply switch 13 ends with the predetermined lifetime. As the
result, the data in the area corresponding to the power supply
switch 13 becomes impossible to be read. In the case of a volatile
memory, the data is also deleted.
[0088] The encryption key storage area 19 is an area for storing
the encryption key to encrypt the data to be recorded. The
encryption key is used also in the case of decoding the encrypted
data. As well as the data security is archived, in the case that
the data effective time elapses to make the data reproduction
impossible, deleting the encryption key makes the decoding
impossible which thereby makes the data reproduction
impossible.
[0089] The encryption circuit 20 is a circuit for encrypting the
data to be recorded on the basis of the encryption key.
Furthermore, it may include a circuit for decoding the data for the
reproduction, or may read the encrypted data and the encryption key
and perform the decoding at the external device such as a personal
computer.
[0090] Incidentally, instead of disposing the performance
deterioration material layer 12 in the memory 1 or 2, the
performance deterioration material may be dispersed within the
organic semiconductor to activate the performance deterioration
material by the predetermined method.
[0091] FIG. 3 illustrates the construction of the conventional
memory 3 for a comparison with the memories 1 and 2 of the present
invention. There is not provided with the protection film 11 and
the performance deterioration material layer 12. There is no
technical concept about the memory lifetime, i.e. the reproduction
effective time of the recorded data.
[0092] Next, the structure of the organic semiconductor element
forming the semiconductor memory element according to the present
invention will be explained.
[0093] First, FIG. 4 illustrates the first element structure in
which a gate 22, an insulator 23, a source 24 and a drain 25 area
disposed on a substrate 21 A semiconductor layer of an organic
semiconductor 26 is further disposed outside of a gate 22, an
insulator 23, a source 24 and a drain 25. A performance
deterioration material 27 is dispersed within the organic
semiconductor 26. Some performance deterioration materials 27 are
directly dispersed and other performance deterioration materials 27
are encapsulated to be dispersed, depending on the activation form
of the performance deterioration material. If the performance
deterioration material 27 activates within the organic
semiconductor 26, the organic semiconductor 26 starts to
deteriorate. And it fails to function as a memory after a
predetermined time period.
[0094] Next, the second element structure includes, as shown in
FIG. 5, the gate 22, the insulator 23, the source 24 and the drain
25 on the substrate 21, and further includes the semiconductor
layer of the organic semiconductor 26 outside of gate 22, the
insulator 23, the source 24 and the drain 25. Furthermore, the
second element structure includes a protection portion 28 outside
of the organic semiconductor 26 on the substrate, and a performance
deterioration material layer 29 above the protection portion 28.
The performance deterioration material layer 29 includes therein
the performance deterioration material 27. If the protection
portion 28 is destroyed, the performance deterioration material 27
diffuses within the organic semiconductor 26, so that the organic
semiconductor 26 starts to deteriorate until it fails to function
as a memory after a predetermined time period.
[0095] FIG. 6 illustrates the conventional element structure in
which the gate 22, the insulator 23, the source 24 and the drain 25
are disposed on the substrate 21, and the organic semiconductor 26
is disposed outside of the gate 22, the insulator 23, the source 24
and the drain 25. It is known that the organic semiconductor 26 is
deteriorated by the moisture or oxygen. Therefore, this
conventional structure, as it is, can be covered by the protection
film or the like to prevent the organic semiconductor 26 from
contacting with the air. Then, the protection film can be destroyed
to cause the operation within the lifetime. Particularly, the
conventional element structure can be directly used, without a
special treatment of the element structure itself.
(First Example of Semiconductor Memory Element according to the
Present Invention)
[0096] In this example, as shown in FIG. 7A, an organic
semiconductor circuit portion 31 and a protection film 32 adjacent
to the circuit portion 31 are disposed on the substrate 21. As
shown in FIG. 7B, heat, pressure, light or the like is applied or
irradiated on the protection film 32 to make cracks 32a in the
protection film 32. Through this cracks 32a, the moisture or oxygen
in the air penetrates into the organic semiconductor circuit
portion 31 and diffuses therein, which deteriorates the function of
the organic semiconductor circuit portion 31. Because the
deterioration in the function of the organic semiconductor circuit
portion 31 progresses, the reproduction of the recorded data
becomes impossible after a predetermined time period.
(Second Example of Semiconductor Memory Element according to the
Present Invention)
[0097] In this example, as shown in FIG. 8, the organic
semiconductor circuit portion 31 and the protection film 32
adjacent to the circuit portion 31 are disposed on the substrate
21. The protection film 32 has an opening portion at a
predetermined portion of the organic semiconductor circuit portion
31. A seal 33 is hermetically disposed above the opening portion.
As shown in FIG. 8B, if the seal 33 is stripped off, the moisture
or oxygen in the air penetrates into the organic semiconductor
circuit portion 31 and diffuses therein to cause the deterioration
in the function of the organic semiconductor circuit portion 31.
Because the deterioration in the function of the organic
semiconductor circuit portion 31 progresses, the data reproduction
becomes impossible after a predetermined time period.
(Third Example of Semiconductor Memory Element according to the
Present Invention)
[0098] In this example, as shown in FIG. 9A, the organic
semiconductor circuit portion 31, the protection film 32 adjacent
to the circuit portion 31 and the performance deterioration
material layer 29 including the performance deterioration material
27 and adjacent to the protection film 32 are disposed on the
substrate 21. As shown in FIG. 9B, heat, pressure, light or the
like is applied or irradiated on the protection film 32 to make
cracks 32a in the protection film 32. Through this cracks 32a, the
performance deterioration material 27 in the performance
deterioration material layer 29 penetrates into the organic
semiconductor circuit portion 31 and diffuses therein to cause the
deterioration in the function of the organic semiconductor circuit
portion 31. Because the deterioration in the function of the
organic semiconductor circuit portion 31 progresses, the
reproduction of the recorded data becomes impossible after a
predetermined time period.
(Fourth Example of Semiconductor Memory Element according to the
Present Invention)
[0099] In this example, as shown in FIG. 10A, the organic
semiconductor circuit portion 31 and the protection film 32
adjacent to the circuit portion 31 are disposed on the substrate
21. Furthermore, the performance deterioration material 27 is
dispersed in the organic semiconductor circuit portion 31. As shown
in FIG. 10B, if the performance deterioration material 27 is
activated by heating, pressurizing, irradiation with light, and the
like, from the top of the protection film 32, the function of the
organic semiconductor circuit portion 31 deteriorates. Because the
deterioration in the function of the organic semiconductor circuit
portion 31 progresses, the reproduction of the recorded data
becomes impossible after a predetermined time period.
[0100] Incidentally, as shown in FIG. 10C, if the performance
deterioration material 27 tends to activate without any treatment,
this material 27 may be encapsulated into a microcapsule 35, which
may be destroyed on the use. The introduction of the microcapsule
35 will be explained in detail below.
[0101] Here, a "time material" (corresponds to the performance
deterioration material herein) and the activation of the time
material will be explained. In the semiconductor memory element of
the present invention, the time material is preliminarily mixed in
a cell constructing the organic semiconductor, and this time
material is activated by releasing a predetermined trigger, so that
the organic semiconductor is deteriorated due to the activated
species in order to intentionally obtain the limited lifetime. The
trigger may be sensing pressure, heat, light or the like.
[0102] Incidentally, some time materials tend to start the
deterioration without the special treatment if they are mixed in
the organic semiconductor. Other time materials do not act on the
organic semiconductor until the trigger is released.
[0103] An example of the former type (time materials tending to
start the deterioration without the special treatment) is benzoyl
peroxides or a so-called photopolymerization initiator having
ketone group or azo group, from which radicals are caused by UV
radiation, encapsulated in microcapsules made of gelatins,
formaldehyde resins or polyurethane resins. The encapsulated
chemicals exit from the microcapsules by means of the trigger and
activated by UV radiation. The moisture may be encapsulated in the
microcapsules so that the organic semiconductor is deteriorated by
the moisture emitted from the microcapsules. Azo compounds may be
encapsulated in the microcapsules so that azo compounds dissolve by
heating and cause generation of nitrogen or nitrogen oxides in a
form of gas and thereby physically cause cracks in the organic
semiconductor layer for the deterioration thereof.
[0104] On the other hand, an example of the latter type (time
materials not acting until the trigger is released) is a so-called
cyanine dye such as cyanines, isocyanines or pseudocyanines having
a heterocycle such as quinolines, thiazoles, pyridines,
benzooxazoles or benzothiazoles. These chemicals are stable unless
light of the absorption wavelength is irradiated, and their
molecular chains are cut by the irradiation with light of the
absorption wavelength and thereby radicals are produced. These
radicals deteriorate the organic semiconductor.
[0105] As explained above, the performance deterioration material
may be used as it is or may be used as encapsulated in the
microcapsule, depending on the type of the performance
deterioration material. Incidentally, also in the following
examples, the aforementioned treatment depending on the type of the
performance deterioration material is employed as well.
(Fifth Example of Semiconductor Memory Element according to the
Present Invention)
[0106] In this example, as shown in FIG. 11, the organic
semiconductor circuit portion 31 and a color film layer 36 adjacent
to the circuit portion 31 are disposed on the substrate 21.
Furthermore, the performance deterioration material 27 is dispersed
in the organic semiconductor circuit portion 31. The light of a
predetermined wavelength is irradiated onto the color film layer 36
from the top so that the irradiated portion of the color film layer
36 obtains the light transmissive property in a wide range. Next,
as shown in FIG. 11B, UV rays is irradiated to activate the
performance deterioration material 27 so that the function of the
organic semiconductor circuit portion 31 deteriorates. Because the
deterioration in the function of the organic semiconductor circuit
portion 31 progresses, the data reproduction becomes impossible
after a predetermined time period.
(Sixth Example of Semiconductor Memory Element according to the
Present Invention)
[0107] In this example, as shown in FIG. 12A, the organic
semiconductor circuit portion 31 and the protection film 32
adjacent to the circuit portion 31 are disposed on the substrate
21. Furthermore, the performance deterioration material 27 is
dispersed in the organic semiconductor circuit portion 31. The
protection film 32 has the opening portion at a position
corresponding to a predetermined portion of the organic
semiconductor circuit portion 31. The opening portion is sealed
with the seal 33. Next, as shown in FIG. 12B, after stripping off
the seal 33, UV rays is irradiated to activate the performance
deterioration material 27 and thereby deteriorate the function of
the organic semiconductor circuit 31. Because the deterioration in
the function of the organic semiconductor circuit portion 31
progresses, the data reproduction becomes impossible after a
predetermined time period. Incidentally, the opening portion may be
full-filled by a transparent material.
(Example of Card-like Semiconductor Memory Element according to the
Present Invention)
[0108] Next, with reference to FIG. 13 to FIG. 15, examples of the
card-like semiconductor memory according to the present invention
will be explained. The organic semiconductor can be fabricated by
using the printing technology, which makes it possible to fabricate
a relatively large size memory such as a card-like memory at a low
cost.
[0109] In a memory card 5, as shown in FIG. 13, a semiconductor
chip 43 is enclosed in a card-like package 41, at one edge of which
electrodes 42 are formed to electrically contact with an external
device. The bonding pads 18 of the memory 1 shown in FIG. 1 for
example may be connected to electrodes 42, so that an electrical
connection between the semiconductor chip 43 and the external
device is established.
[0110] The semiconductor chip 43 used for the memory card 5 is the
organic semiconductor in a form shown in FIGS. 7A-7B, or shown in
FIGS. 10A-10C. In this case, the crack 32a is caused in the
protection layer by heating or pressurizing or irradiation with
light from the top of the semiconductor chip 43, so that the
moisture or oxygen in the air diffuses in the semiconductor circuit
portion 31 made of the organic semiconductor and thereby the
deterioration in the organic semiconductor progress. The data
reproduction is performable within the lifetime.
[0111] In a memory card 6, as shown in FIG. 14, the semiconductor
chip 43 is enclosed in the card-like package 41, at one edge of
which electrodes 42 are formed to contact with the external device.
For example, the bonding pads 18 of the memory 1 shown in FIG. 1
are connected to the electrodes 42 to establish the electrical
connection between the semiconductor chip 43 and the external
device. The top portion of the semiconductor 43 is covered with the
color film layer 36.
[0112] The semiconductor chip 43 used for the memory card 36 is the
organic semiconductor in a form shown in FIGS. 11A-11B. In this
case, the light of the predetermined wavelength is irradiated onto
the color film layer 36, and then UV rays is irradiated to activate
the performance deterioration material 27 dispersed in the
semiconductor circuit portion 31, so that the deterioration in the
organic semiconductor progresses and allows the record data
reproduction within the lifetime.
[0113] In a memory card 7, as shown in FIG. 15, the semiconductor
chip 43 is enclosed in the card-like package 41, at one edge of
which electrodes 42 are formed to contact with the external device.
For example, the bonding pads 18 of the memory 1 shown in FIG. 1
may be connected to the electrodes 42 to establish the electrical
connection between the semiconductor chip 43 and the external
device. The semiconductor chip 43 has the opening portion at the
top portion thereof, which is sealed with the seal 33. An ear
portion 33a is formed at the tip of the seal 33 to facilitate the
stripping.
[0114] The semiconductor chip 43 used for the memory card 7 is the
organic semiconductor in a form shown in FIGS. 8A-8B, or shown in
FIGS. 12A-12B. In the case of the organic semiconductor shown in
FIGS. 8A-8B, if the seal 33 is stripped off, the moisture or oxygen
in the air diffuses in the semiconductor circuit portion 31, so
that the deterioration in the organic semiconductor progresses and
the data reproduction is allowed within the lifetime.
[0115] On the other hand, in the case of the organic semiconductor
shown in FIGS. 12A-12B, after the seal 33 is stripped off, UV rays
is irradiated to activate the performance deterioration material 27
dispersed in the semiconductor circuit portion 31, so that the
deterioration in the organic semiconductor progresses and the
record data reproduction is allowed within the lifetime. In order
to avoid the influence by the moisture or oxygen in the air, the
opening portion may be covered with a light transmissive material.
It is particularly effective in a form in which the deterioration
speed and thereby the lifetime are controlled by UV irradiation
amount.
[0116] Additionally, a card form can be off course made from the
organic semiconductor shown in FIGS. 9A-9B. Also in this case, the
crack 32a is caused in the protection film 32 by heating or
pressurizing, or irradiation with light and so on, so that the
performance deterioration material 27 in the performance
deterioration material layer 29 diffuses in the semiconductor
circuit portion 31 and thereby the deterioration in the organic
semiconductor progresses, and the record data reproduction is
allowed within the lifetime.
(Lifetime Operation Starting Apparatus for Semiconductor Memory
Element according to the Present Invention)
[0117] An example of the lifetime operation starting apparatus for
the semiconductor memory element according to the present invention
will be explained, with reference to FIG. 16. This example is a
device for releasing the trigger to start the lifetime of the
aforementioned memory card, and for recording and reproducing the
data.
[0118] The lifetime operation starting apparatus 8 is used for the
organic semiconductor optically causing the performance
deterioration as shown in FIGS. 7A-7B, FIGS. 9A-9B, or FIGS.
11A-11B. It is provided with a handling portion 51; a light source
52; an electrode 53; a control portion 54; a light source drive
portion 55; a data record and reproduction portion 56, as shown in
FIG. 16.
[0119] The operation portion 51 is for inputting an operational
command to the lifetime operation starting apparatus 8. The light
source 52 is for irradiating the light onto the semiconductor chip
43 of the memory card 6 to diffuse the performance deterioration
material 27 in the organic semiconductor portion or activate the
performance deterioration material 27. The electrode 53 contacts
with the electrode 42 of the memory card 6 to supply the electrical
power, input or output the record/reproduction control signal or
the data. The control portion 54 is for controlling the entire
operation of the apparatus. The light source drive portion 55 is
for turning on the light source 52 under a control of the control
portion 54. Furthermore, the data record and reproduction portion
56 is for writing (recording) the data on to the memory card 6 or
reading (reproducing) the data. Additionally, the multipurpose
function for the apparatus, such as display function, is
employed.
[0120] The deterioration of the memory card 6 is started by the
irradiation with light from the light source 52, allowing the data
reproduction within the lifetime. For example, in the rental
business of music or video soft, the irradiation time of the light
can be controlled depending on the rental fee when the data is
recorded, so that the lifetime can be set.
[0121] Incidentally, it will be obvious to those skilled in the art
that the invention is not limited to the aforementioned structure,
and the seal strip structure is provided in the case of the memory
card in a form sealed with the seal as shown in FIGS. 8A-8B or
FIGS. 12A-12B, or the heating means or pressure means is provided
in the case of the memory card in a form involving the heat or
pressure application as shown in FIGS. 10A-10C.
[0122] As explained above, according to the semiconductor memory
element and the lifetime operation starting apparatus therefor
according to the present invention, the reproduction time of the
recorded data, i.e. the start time of the reproducible lifetime can
be freely set. Furthermore, the lifetime itself can be freely set.
Furthermore, since the semiconductor memory element is made of the
organic semiconductor, the semiconductor memory element suitable
for the mass production at a low cost is presented.
[0123] The present invention is not limited to the aforementioned
examples and can be modified as appropriate within a range not
departing from the essence or spirit of the invention read from
claims and the whole specification. The semiconductor memory
element and the lifetime operation apparatus therefore involving
such a modification are all encompassed within a scope of the
invention.
INDUSTRIAL APPLICABILITY
[0124] The semiconductor memory element and the lifetime operation
starting apparatus therefor according to the present invention are
applicable to various memory elements and various record devices
for recording at high density and reproducing a large amount of
information including various contents information such as video
information or audio information, various data information for
computers, or control information, by means of the organic
semiconductor available at a relatively low cost and suitable for
downsizing in its scale or thickness.
* * * * *