U.S. patent application number 11/309357 was filed with the patent office on 2007-07-26 for organic memory device and method of fabricating the same.
Invention is credited to Chia-Chieh Chang, Wen-Miao Lo, Zing-Way Pei.
Application Number | 20070170420 11/309357 |
Document ID | / |
Family ID | 38284648 |
Filed Date | 2007-07-26 |
United States Patent
Application |
20070170420 |
Kind Code |
A1 |
Chang; Chia-Chieh ; et
al. |
July 26, 2007 |
ORGANIC MEMORY DEVICE AND METHOD OF FABRICATING THE SAME
Abstract
An organic memory device includes a top electrode, a bottom
electrode, and a bistable organic polymer layer between the top and
bottom electrodes. Moreover, the organic memory device further
includes a surface treatment layer between the organic polymer
layer and the bottom electrode. Because the surface treatment layer
can stabilize the interface between the organic polymer layer and
the bottom electrode, the reliability of the device may be
promoted.
Inventors: |
Chang; Chia-Chieh; (Taipei
City, TW) ; Pei; Zing-Way; (Taichung City, TW)
; Lo; Wen-Miao; (Kaohsiung City, TW) |
Correspondence
Address: |
JIANQ CHYUN INTELLECTUAL PROPERTY OFFICE
7 FLOOR-1, NO. 100, ROOSEVELT ROAD, SECTION 2
TAIPEI
100
omitted
|
Family ID: |
38284648 |
Appl. No.: |
11/309357 |
Filed: |
July 31, 2006 |
Current U.S.
Class: |
257/40 |
Current CPC
Class: |
G11C 13/0014 20130101;
G11C 13/0016 20130101; G11C 2213/51 20130101; H01L 51/105 20130101;
B82Y 10/00 20130101; H01L 27/285 20130101; H01L 51/0591
20130101 |
Class at
Publication: |
257/40 |
International
Class: |
H01L 29/08 20060101
H01L029/08 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 11, 2006 |
TW |
95101034 |
Claims
1. An organic memory device, comprising a top electrode, a bottom
electrode, and a polymer thin film disposed between the top
electrode and the bottom electrode, wherein the organic memory
device further includes: a bottom surface treatment layer disposed
between the polymer thin film and the bottom electrode to stabilize
interface between the polymer thin film and the bottom
electrode.
2. The organic memory device as claimed in claim 1, wherein the
bottom surface treatment layer includes a metal oxide layer, a
metal nitride layer, a silicon oxide layer, a silicon nitride
layer, or an organic self-assembling polymer layer.
3. The organic memory device as claimed in claim 1, further
comprising a top surface treatment layer disposed between the
polymer thin film and the top electrode to stabilize interface
between the polymer thin film and the top electrode stable.
4. The organic memory device as claimed in claim 3, wherein the top
surface treatment layer includes a metal oxide layer, a metal
nitride layer, a silicon oxide layer, a silicon nitride layer, or
an organic self-assembling polymer layer.
5. The organic memory device as claimed in claim 1, wherein the top
electrode and the bottom electrode includes metal.
6. The organic memory device as claimed in claim 5, wherein the
bottom electrode includes aluminum or copper.
7. The organic memory device as claimed in claim 1, wherein the
polymer thin film has a bistable structure.
8. A method of fabricating an organic memory device, comprising:
forming a bottom electrode on a substrate; performing a first
surface treatment on the bottom electrode to form a bottom surface
treatment layer on a surface thereof; forming a polymer thin film
on the bottom surface treatment layer; and forming a top electrode
on the polymer thin film.
9. The method of fabricating an organic memory device as claimed in
claim 8, wherein the first surface treatment includes an oxidation
treatment or a nitridation treatment.
10. The method of fabricating an organic memory device as claimed
in claim 9, wherein the first surface treatment includes an O.sub.2
plasma treatment, an N.sub.2 plasma treatment, or an NH.sub.3
plasma treatment.
11. The method of fabricating an organic memory device as claimed
in claim 8, wherein the first surface treatment includes a thermal
treatment performed in an oxygen, nitrogen or an ammonia gas
atmosphere.
12. The method of fabricating an organic memory device as claimed
in claim 8, wherein performing the first surface treatment on the
bottom electrode includes depositing or coating the bottom surface
treatment layer on the bottom electrode.
13. The method of fabricating an organic memory device as claimed
in claim 12, wherein the bottom surface treatment layer includes a
silicon oxide layer or a silicon nitride layer.
14. The method of fabricating an organic memory device as claimed
in claim 12, wherein the bottom surface treatment layer includes an
organic self-assembling polymer.
15. The method of fabricating an organic memory device as claimed
in claim 8, further comprising a step of performing a second
surface treatment on the polymer thin film to form a top surface
treatment layer on the polymer thin film after the step of forming
the polymer thin film and before forming the bottom electrode.
16. The method of fabricating an organic memory device as claimed
in claim 15, wherein the second surface treatment is performed at a
temperature below melting point of the polymer thin film.
17. The method of fabricating an organic memory device as claimed
in claim 15, wherein the second surface treatment includes
introducing a reaction gas containing oxygen, nitrogen or ammonia
to make the interface between the polymer thin film and the top
electrode to be an oxide interface or a nitride interface before
the step of forming the top electrode.
18. The method of fabricating an organic memory device as claimed
in claim 15, wherein the step of performing the second surface
treatment on the polymer thin film comprises depositing or coating
the top surface treatment layer on the polymer thin film.
19. The method of fabricating an organic memory device as claimed
in claim 18, wherein the top surface treatment layer includes a
silicon oxide layer or a silicon nitride layer.
20. The method of fabricating an organic memory device as claimed
in claim 18, wherein the top surface treatment layer includes a
self-assembling silicon oxide layer.
21. The method of fabricating an organic memory device as claimed
in claim 8, wherein the top electrode and the bottom electrode
include metal.
22. The method of fabricating the organic memory device as claimed
in claim 8, wherein the polymer thin film comprises a bistable
structure.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the priority benefit of Taiwan
application serial no. 95101034, filed on Jan. 11, 2006. All
disclosure of the Taiwan application is incorporated herein by
reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an organic memory device
and a method of fabricating the same. More particularly, the
present invention relates to an organic memory device with high
device reliability and a method of fabricating the same.
[0004] 2. Description of Related Art
[0005] With the approach of the nanometer age, recently a new
nanometer memory with a larger storage capacity, higher speed, and
better performance and adaptability has attracted much attention.
Among various new non-volatile memories, one of the most
interesting memories is the organic memory.
[0006] The organic memory utilizes the memory effect of organic
materials to store data. Therefore, all organic materials with
bistable memory effects may be used in memory devices. The
technique that employs organic polymer thin films to fabricate
organic memories is under rapid development, and may be combined
with the existing film coating techniques in the industry. For
example, multilayer organic films structure comprising multiple
organic polymer thin films may be fabricated to form high density
memories using the existing mature semiconductor process. Moreover,
the organic memory has an additional advantageous feature that
other nanometer memory techniques, such as magnetic memory and
phase change memory, do not possess, i.e., low-cost flexible
memories and electronic devices can be fabricated by applying
non-semiconductor film coating techniques (e.g. processes of an
evaporation technique for OLED, a screen coating technique, or an
inkjet technique) with soft materials or surfaces of irregular
objects used as substrates.
[0007] However, there exist difficulties in reading and writing
memory devices formed of organic materials and non-organic
materials (e.g. metal electrodes) due to the poor electrical
property caused by the contact interface.
SUMMARY OF THE INVENTION
[0008] Accordingly, an object of the present invention is to
provide an organic memory device, wherein the adhesion between the
metal electrodes and the polymer thin film is improved. Thus, the
reliability of the device may be effectively promoted.
[0009] Another object of the present invention is to provide a
method of fabricating the organic memory device, wherein the
interface between the metal electrodes and the polymer thin film
may be improved. Thus, the interface between the metal electrodes
and the polymer thin film may be stabilized and the number of
carrier traps caused by interface defects may be reduced.
[0010] The present invention provides an organic memory device
comprising a top electrode, a bottom electrode and a polymer thin
film. The polymer thin film is disposed between the top electrode
and bottom electrode. The memory device further includes a bottom
surface treatment layer between the polymer thin film and the
bottom electrode, so as to form a stable interface.
[0011] According to an embodiment of the present invention, the
aforementioned bottom surface treatment layer includes a metal
oxide layer, a metal nitride layer, a silicon oxide layer or an
organic self-assembling polymer layer.
[0012] According to an embodiment of the present invention, the top
electrode and bottom electrode may comprise a metal. The bottom
electrode may comprise aluminum or copper.
[0013] According to an embodiment of the present invention, the
aforementioned polymer thin film may comprise a bistable
structure.
[0014] According to an embodiment of the present invention, the
organic memory device further comprise an additional top surface
treatment layer disposed between the polymer thin film and the top
electrode.
[0015] The present invention also provides a method of fabricating
the organic memory device including forming a bottom electrode on a
substrate; performing a first surface treatment on the bottom
electrode to form a bottom surface treatment layer on the surface
of the bottom electrode; forming a polymer thin film on the surface
treatment layer; and forming a top electrode on the polymer thin
film.
[0016] According to an embodiment of the present invention, the
first surface treatment comprises, for example an oxidation
treatment including an O.sub.2 plasma treatment or a nitridation
treatment including an N.sub.2 plasma treatment or an NH.sub.3
plasma treatment.
[0017] According to an embodiment of the present invention, the
aforementioned first surface treatment includes a thermal treatment
performed in an oxygen, a nitrogen, or an ammonia gas
atmosphere.
[0018] According to an embodiment of the present invention, the
first surface treatment applied to the bottom electrode includes
depositing or coating the aforementioned bottom surface treatment
layer on the bottom electrode. The bottom surface treatment layer
comprises a silicon oxide layer or a silicon nitride layer or an
organic self-assembling polymer.
[0019] According to an embodiment of the present invention, the
polymer thin film may be optionally subjected to a second surface
treatment, after the aforementioned polymer thin film is formed but
before the top electrode is formed so as to form a second top
surface treatment layer over the surface of the polymer thin film.
The surface treatment may also stabilize the interface between the
organic thin film and the inorganic conductor. Preferably, the top
surface treatment is completed at a temperature below the glass
transition temperature of the polymer thin film. Furthermore, the
surface treatment includes introducing a reaction gas containing
oxygen, nitrogen or ammonia before the formation of the top
electrode, so that the interface between the polymer thin film and
the top electrode is an oxide interface or a nitride interface.
Alternatively, the top surface treatment layer may be deposited or
coated on the polymer thin film. The top surface treatment layer
comprises a silicon oxide layer or a silicon nitride layer or a
self-assembling silicon oxide layer.
[0020] According to an embodiment of the present invention, the top
electrode and bottom electrode may comprise a metal. In addition,
the polymer thin film comprises a bistable structure.
[0021] According to an embodiment of the present invention, a
bottom surface treatment layer is added into the structure of the
organic memory in order to stabilize the interface between the
polymer thin film and the bottom electrode and thereby reduce the
number of carrier traps caused by interface defects. Furthermore,
the adhesion between the metal electrodes and the polymer thin film
may also be improved. Thus, the reliability of the device may be
effectively promoted.
[0022] In order to the make aforementioned and other objects,
features and advantages of the present invention comprehensible,
preferred embodiments accompanied with figures are described in
detail below.
[0023] It is to be understood that both the foregoing general
description and the following detailed description are exemplary,
and are intended to provide further explanation of the invention as
claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIGS. 1A-1C are sectional views illustrating the process
steps of fabricating an organic memory device in accordance with an
embodiment of the present invention.
DESCRIPTION OF EMBODIMENTS
[0025] FIGS. 1A-1C are sectional views illustrating the process
steps of fabricating an organic memory device in accordance with an
embodiment of the present invention.
[0026] Referring to FIG. 1A, a layer of bottom electrode 102
comprised of aluminum or copper is formed on a substrate 100. Next,
the bottom electrode 102 is treated with a first surface treatment
104 to form a bottom surface treatment layer 106 on the surface of
the bottom electrode 102, wherein the thickness of the bottom
surface treatment layer 106 is below several tens of nanometers
according to the device design requirement. The first surface
treatment 104 comprises, for example, an oxidation treatment
including an O.sub.2 plasma treatment or a nitridation treatment
including, an N.sub.2 plasma treatment or an NH.sub.3 plasma
treatment. In addition, the aforementioned first surface treatment
104 may also include a thermal treatment in oxygen, nitrogen or
ammonia gas atmosphere. Furthermore, the first surface treatment
104 applied to the bottom electrode 102 may also includes
depositing or coating the bottom surface treatment layer 106, for
example, a silicon oxide layer, a silicon nitride layer or an
organic self-assembling polymer on the bottom electrode 102. The
bottom surface treatment layer 106 formed by the aforementioned
first surface treatment 104 in spite of using the above method or
any other method, includes a metal oxide layer, a metal nitride
layer, a silicon oxide layer, a silicon nitride layer, or an
organic self-assembling polymer layer.
[0027] Next, referring to FIG. 1B, a layer of polymer thin film 108
is formed on the bottom surface treatment layer 106 using an
evaporation technique, a screen coating technique or an inkjet
technique, and the thickness of the polymer thin film 108 may be
several tens of nanometers depending on the device design
requirement. The layer of polymer thin film 108 comprises, for
example, a bistable structure including a mixture of polystyrene
(PS), 8-hydroxyquinoline (8HQ) and Au, or any bistable organic
substances.
[0028] Next, referring to FIG. 1C, a top electrode 110 is formed on
the polymer thin film 108, wherein the material of the top
electrode 110 includes metal. The structure shown in FIG. 1C is the
organic memory device of the preferred embodiment of the present
invention.
[0029] Additionally, the top electrode 110 may be formed on a
optional top surface treatment layer (not shown) that is formed by
treating the polymer thin film 108 with a second surface treatment,
wherein the thickness of the top surface treatment layer is below
several tens of nanometers according to the device design
requirement. The aforementioned second surface treatment includes,
for example, introducing a reaction gas containing oxygen, nitrogen
or ammonia before the formation of the top electrode 110, such that
the interface between the polymer thin film 108 and the top
electrode 110 may be an oxide interface or a nitride interface.
Furthermore, the aforementioned second surface treatment applied to
the polymer thin film 108 may also include depositing or coating a
top surface treatment layer, for example, a silicon oxide layer, a
silicon nitride layer, or a self-assembling silicon oxide layer on
the polymer thin film 108. Preferably, the aforementioned second
surface treatment is performed at a temperature below the glass
transition temperature of polymer thin film 108. The top surface
treatment layer formed by the aforementioned second surface
treatment in spite of by using the above method or any other
method, includes a metal oxide layer, a metal nitride layer, a
silicon oxide layer, a silicon nitride layer, or an organic
self-assembling polymer layer.
[0030] To sum up, the present invention is characterized in
disposing the bottom surface treatment layer between the polymer
thin film and the bottom surface treatment layer of the bottom
electrode to improve the stability of the interface. Furthermore, a
top surface treatment layer may be optionally formed between the
polymer thin film and the top electrode. Thus, the number of
carrier traps caused by interface defects may be effectively
reduced, and the adhesion between metal electrodes and the polymer
thin film may be promoted. Thus, the reliability of the organic
memory device may be effectively promoted.
[0031] It will be apparent to those skilled in the art that various
modifications and variations can be made to the structure of the
present invention without departing from the scope or spirit of the
invention. In view of the foregoing, it is intended that the
present invention cover modifications and variations of this
invention provided they fall within the scope of the following
claims and their equivalents.
* * * * *