U.S. patent application number 11/299108 was filed with the patent office on 2006-05-04 for programmable mask and method for fabricating biomolecule array using the same.
Invention is credited to Chi Hoon Jun, Moon Youn Jung, Young Shin Kim, Yun Tae Kim, Dong Ho Shin, Hae Sik Yang.
Application Number | 20060094144 11/299108 |
Document ID | / |
Family ID | 36261361 |
Filed Date | 2006-05-04 |
United States Patent
Application |
20060094144 |
Kind Code |
A1 |
Jung; Moon Youn ; et
al. |
May 4, 2006 |
Programmable mask and method for fabricating biomolecule array
using the same
Abstract
A programmable mask used in a photolithography process for
fabricating a biomolecule array and a method for fabricating a
biomolecule array using the same are disclosed. Particularly, a
TFT-LCD type programmable mask for selectively transmitting
incident light in accordance with an electrical signal applied
thereto and a method for fabricating a biomolecule array using the
same are provided. The ultraviolet light is selectively illuminated
to a sample substrate so that the biomolecule array having high
density can be fabricated.
Inventors: |
Jung; Moon Youn; (Yusong-Gu,
KR) ; Yang; Hae Sik; (Seo-Gu, KR) ; Jun; Chi
Hoon; (Yusong-Gu, KR) ; Kim; Yun Tae;
(Yusong-Gu, KR) ; Kim; Young Shin; (Yusong-Gu,
KR) ; Shin; Dong Ho; (Yusong-Gu, KR) |
Correspondence
Address: |
BLAKELY SOKOLOFF TAYLOR & ZAFMAN
12400 WILSHIRE BOULEVARD
SEVENTH FLOOR
LOS ANGELES
CA
90025-1030
US
|
Family ID: |
36261361 |
Appl. No.: |
11/299108 |
Filed: |
December 8, 2005 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10246593 |
Sep 18, 2002 |
|
|
|
11299108 |
Dec 8, 2005 |
|
|
|
Current U.S.
Class: |
438/30 ;
257/E27.13 |
Current CPC
Class: |
B82Y 30/00 20130101;
B01J 2219/00689 20130101; G02F 2203/12 20130101; G02F 1/216
20130101; H01L 27/146 20130101; B01J 2219/00608 20130101; B01J
2219/00434 20130101; B01J 2219/00529 20130101; B01J 2219/00722
20130101; C40B 60/14 20130101; B01J 2219/00527 20130101; B01J
2219/00711 20130101; G02F 1/133528 20130101; G02F 1/13454 20130101;
G02F 1/13725 20130101; C40B 40/06 20130101; G03F 7/7035 20130101;
B01J 2219/00675 20130101; G03F 7/70291 20130101; B01J 19/0046
20130101; B01J 2219/00596 20130101; B01J 2219/00605 20130101; B01J
2219/00659 20130101; B01J 2219/00677 20130101 |
Class at
Publication: |
438/030 |
International
Class: |
H01L 21/00 20060101
H01L021/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 15, 2002 |
KR |
2002-26698 |
Claims
1. A biomolecule array fabricating apparatus, comprising:
programmable mask; ultraviolet light; support base supports the
programmable mask above sample substrate to be formed with
biomolecule; and computer outputs programmed data to operate a
desired transistor in the programmable mask; wherein the
programmable mask, including: a lower substrate of which an upper
surface has a polysilicon thin film transistor for switching a
pixel area in accordance with an electrical signal applied thereto,
a lower pixel electrode connected to the drain electrode of said
thin film transistor, and an orientation film formed on said lower
pixel electrode and said thin film transistor, and of which an
lower surface has a polarizer formed thereon; an upper substrate of
which an lower surface has an upper pixel electrode and an
orientation film formed under said upper pixel electrode, and of
which an upper surface has a polarizer formed thereon; liquid
crystals injected between said lower substrate and said upper
substrate and varied in accordance with a voltage applied thereto
to selectively transmit the ultraviolet light; and a driving
circuit formed on the upper surface of said lower substrate, for
driving the polysilicon thin film transistor in said pixel
area.
2. The biomolecule array fabricating apparatus according to claim
1, wherein said polarizer has a high transmissivity with respect to
ultraviolet light having wavelength of 330-400 nm and is composed
of a polymer film which is not deactivated by said ultraviolet
light.
3. The biomolecule array fabricating apparatus according to claim
2, wherein said polymer film is composed of polyvinyl alcohol, and
said inorganic crystal is composed of calcite, quartz, or
tourmaline.
4. The biomolecule array fabricating apparatus according to claim
1, wherein further comprises a shielding film formed on said upper
substrate or said lower substrate for shielding the ultraviolet
light incident from aid thin film transistor.
5. The biomolecule array fabricating apparatus according to claim
1, wherein further comprises a depolarizer for changing the
ultraviolet light incident to the lower portion of said lower
substrate to non-polarized light.
6. The biomolecule array fabricating apparatus according to claim
1, wherein said polarizer has a high transmissivity with respect to
ultraviolet light having wavelength of 330-440 nm and is composed
of a substance which is not deactivated by said ultraviolet
light.
7. The biomolecule array fabricating apparatus according to claim
6, wherein said, wherein said substance which is not deactivated by
said ultraviolet light is a polyimid film resistant to the
ultraviolet light, a silicon oxide film formed by a slope
sputtering method or a slope thermal deposition method, or a
diamond-like-carbon (DLC) film for allowing the liquid crystal to
be oriented by illuminating an ion beam.
8. A biomolecule array fabricating apparatus, comprising:
programmable mask; ultraviolet light; supprort base supports the
programmable mask above sample substrate to be formed with
biomolecule; and computer outputs programmed data to operate a
desired transistor in the programmable mask; wherein the
programmable mask, including: a lower substrate of which an upper
surface has a polysilicon thin film transistor for switching a
pixel area in accordance with an electrical signal, a lower pixel
electrode connected to the drain electrode of said thin film
transistor, and an orientation film formed on said lower pixel
electrode and said thin film transistor; an upper substrate of
which an lower surface has an upper pixel electrode and an
orientation film formed under said upper pixel electrode, and of
which an upper surface has a polarizer formed thereon; Guest-Host
liquid crystal injected between said lower substrate and said upper
substrate, for shielding or transmitting light by allowing the
oscillation direction of linearly-polarized light to be equal or
orthogonal to the light absorbing axis of a dye in accordance with
a voltage applied thereto; and a driving circuit formed on the
upper surface of said lower substrate, for driving the polysilicon
thin film transistor in said pixel area.
9. The biomolecule array fabricating apparatus according to claim
8, wherein said polarizer has a high transmissivity with respect to
ultraviolet light having wavelength of 330-440 nm and is composed
of a polymer film which is not deactivated by said ultraviolet
light.
10. The biomolecule array fabricating apparatus according to claim
9, wherein said polymer film is composed of polyvinyl alcohol, and
said inorganic material is composed fo calcite, quartz, of
tourmaline.
11. The biomolecule array fabricating apparatus according to claim
8, wherein further comprises a shielding film formed on said upper
substrate or said lower substrate for shielding the ultraviolet
light incident from said thin film transistor.
12. The biomolecule array fabricating apparatus according to claim
8, wherein further comprises a depolarizer for changing the
ultraviolet light incident to the lower portion of said lower
substrate to non-polarized light.
13. The biomolecule array fabricating apparatus according to claim
8, wherein said polarizer has a high transmissivity with respect to
ultraviolet light having wavelength of 330-440 nm and is composed
of a substance which is not deactivated by said ultraviolet
light.
14. The biomolecule array fabricating apparatus according to claim
13, wherein said substance which is not deactivated by said
ultraviolet light is a polyimid film resistant to the ultraviolet
light, a silicon oxide film formed by a slope sputtering method or
a slope thermal deposition method, or a diamond-like-carbon (DLC)
film for allowing the liquid crystal to be oriented by illuminating
an ion beam.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a programmable mask adapted
for fabricating a biomolecule array and a method for fabricating a
biomolecule array using the same, more particularly, to a
programmable mask adapted for fabricating the biomolecule array
such as DNA by illuminating ultraviolet light to a specific cell
and a method for fabricating a biomolecule array using the
same.
[0003] 2. Description of the Prior Art
[0004] First, in a biomolecule or a macromolecule array formed on a
substrate, the area composed of a kind of the biomolecule or the
macromolecule is referred as a cell.
[0005] The research for the operation for performing the plurality
of experiment at once by using the biomolecule or macromolecule
array has been progressed. As the biomolecule or macromolecule
array, there are, for example, polypeptide, carbohydrate, and
nucleic acid (DNA, RNA) arrays. The most important thing in the
research is to fabricate an inexpensive array having high density
on the substrate, effectively.
[0006] At the present time, as the method for fabricating the
biomolecule or macromolecule array, there are a spotting method for
dropping a biochemical material to a desired location by moving a
micro-robot in three dimensions, a photolithography method for
selectively illuminating light to the desired location to vary the
surface thereof so that the coupling reaction between the surface
and the biomolecule is generated in only a specific location, and
an electric addressing method for adjusting the electrode voltage
of a microelectrode array to attach the biomolecule to only a
specific electrode.
[0007] The spotting method includes a contact printing method for
adhering a solution on a paper like as a seal is affixed and a
non-contact printing method for dropping the solution. The contact
printing method is progressed in order of a loading step, a
printing step, and a washing step, by using a XYZ robot. Since this
method uses a pin the end of which is formed with a groove like the
point of a fountain pen, the volume of the sample can be
reproducibly adjusted and a plurality of printing steps can be
performed when the sample is loaded one time. However, this method
has a demerit which the number of the arrays per the unit area can
be not increased. As the non-contact printing method, there are a
dispensing method and an ink-jet printing method. The dispensing
method is the method for dropping the solution like as a
micropipette is used, and the ink-jet printing method is the method
which a fine pressure is applied to a reservoir such that the
solution blows off. If the ink-jet printing method is used, the
volume of the sample solution can be finely adjusted to nano-liter
such that the number of the arrays per the unit area can be
remarkably increased. In this method, every sample solution needs
the reservoir, but the number of the reservoirs which can be
provided to the robot is limited. Accordingly, this method can be
used in only case where the array is fabricated by using only a few
sample solutions.
[0008] Affymetrix corporation firstly use the photolithography
method in a semiconductor manufacturing process (U.S. Pat. No.
5,959,098). When the ultraviolet light is selectively illuminated
to, the molecule immobilized to the surface of the substrate and
having, protecting groups by using a photomask, the protecting
group falls out and OH group appears. When the solution including
biomolecule or macromolecule monomer to be attached is dropped, the
biomolecule or macromolecule monomer is fixed to only the portion
in which the OH group appears. Since another protection group is
present in this attached macromolecule monomer, another monomer can
be attached when the light is selectively illuminated. Therefore,
the biomolecule or macromolecule array having a desired array can
be fabricated by repeatedly performing these operations. This
method can fabricate the array having high density and synthesize
in parallel. However, since a plurality of photomask are required,
this method brings out a problem that it takes much time and cost.
Accordingly, the method for fabricating the array by operating the
micromirror of a micromirror array without using the photomask was
developed (U.S. Pat. No. 6,271,957). This method brings out
problems that the complex optical system is required and only a
mosaic pattern can be obtained.
[0009] The electronic addressing method is the method for attaching
the biomolecule by using the voltage controlling function of the
microelectrode array, and includes a method for moving the
biomolecule having a charge into electrode surface to generate
physical or chemical coupling and a method for attaching the
biomolecule within thin film when the thin film is formed by an
electrochemical deposition (Cosnier, Serge, "Biomolecule
immobilization on electrode surfaces by entrapment or attachment to
electochemically polymerized films. A review" Biosensors &
Bioelectronics 14: pp. 443-456 (1999)). For example, since the DNA
has many a negative charge, DNA moves toward the electrode if the
electrode has positive charges. At this time, if the physical or
chemical coupling between the DNA and the electrode is generated,
the DNA is attached to the electrode (U.S. Pat. No. 5,605,662).
Such electrode addressing method brings out problems that it can be
not applied to the case where a number of arrays are used and a
microelectrode array is required. In addition, a method for
electrochemically changing pH around the electrode to attach the
biomolecule to the selected location was developed, and Combimatrix
corporation discloses a method for combining an oligonucleotide to
the selected location of the microelectrode by using this concept
(U.S. Pat. No. 6,090,302). However, in this method, there is a
problem that the yield of each reaction is low, thereby the degree
of purity of each cell is low.
[0010] As the method for fabricating the biomolecule or
macromolecule, a method using a LCD (liquid crystal display) type
programmable mask which the transmission of the light can be
adjusted without using the micromirror array was disclosed (U.S.
Pat. No. 6,271,957, Korean Patent Publication No. 2001-2915). In
the LCD type programmable mask, the operation for adjusting the
transmission of the light in each pixel to generate optical
reaction in the cell on the substrate is repeatedly performed,
thereby the biomolecule or macromolecule array is fabricated.
However, the LCD type programmable mask has problems in a point of
view of polarization, UV transmission, and deactivation due to
ultraviolet light. Accordingly, the programmable mask satisfies the
next facts.
[0011] First, since the light output from the general LCD is
polarized and the protection group on the substrate generally
exists therein without orientation, every protection group exist in
a specific cell on the substrate can not be stripped by the light
output from the LCD. Accordingly, in order to increase the reaction
yield in fabricating the array, the device for changing the light
output from the LCD to the non-polarized light is needed.
[0012] Second, in the general LCD, the light in range of the
visible ray is transmitted, but, in order to strip the protection
group, the ultraviolet light having wavelength of 330-400 nm is
required. In case of an orientation film and a polarizer provided
in the general LCD, since it is readily deactivated the
deactivation due to the ultraviolet light, the orientation film and
the polarizer which are not affected by the ultraviolet light must
be used. Also, the orientation film and the polarizer whose the
absorption of the ultraviolet light is low must be used.
[0013] Third, in case of the TFT-LCD type programmable mask, a
light shield field (a black matrix) can prevent the transistor from
be affected by the ultraviolet light, but an amorphous silicon
transistor of the driving circuit can be affected by scattered
ultraviolet light. This is the demerit of the conventional
programmable mask. Also, since the amorphous silicon transistor has
dark-conductivity higher than photo-conductivity by 10.sup.6 times,
it can not function as a switching element, thereby the arranged
state of the liquid crystal can not be adjusted.
[0014] Fourth, in order to strip the protection group in synthesis
of the DNA, the suitable illumination dose of the light is
required. In necessary, the synthesis must be performed, changing
the wavelength of a small dose of the light. Since the illumination
dose of the light depends on the intensity of the light source, the
illuminated time of the light, the transmissivity of the LCD type
programmable mask, the illumination dose of the light must be
adjusted by electrically adjusting the transmission of the
programmable mask.
[0015] Fifth, if the ultraviolet light is illuminated to the
biomolecule, the reaction or the deactivation therein may be
generated. In order to prevent this, only the ultraviolet light
having a narrow wavelength range which can strip the protection
group without affecting the biomolecule must be illuminated to the
cell.
[0016] Sixth, in order to maximize the number of the cells per the
unit area to fabricate the biomolecule array having high density,
the number of the pixels in the LCD must be minimized. In order to
reduce the size of the pixel, the LCD with a built-in driving
circuit must be manufactured.
[0017] As mentioned above, in order to fabricate the biomolecule or
the macromolecule array, the LCD type programmable mask which can
solve the above-mentioned problems is required.
SUMMARY OF THE INVENTION
[0018] Thus, the object of the present invention is to provide a
LCD type programmable mask in which the protection group within a
specific cell on a sample substrate can be readily stripped and the
illumination dose of the light can be adequately adjusted so that
the biomolecule array having high density can be fabricated.
[0019] The another object of the present invention is to provide a
method for fabricating the biomolecule array having high density by
using said programmable mask.
[0020] A programmable mask according to one embodiment of the
present invention comprises a lower substrate of which an upper
surface has a polysilicon thin film transistor for switching a
pixel area in accordance with an electrical signal applied thereto,
a lower pixel electrode composed of a transparent electrode and
connected to the drain electrode of said thin film transistor, and
an orientation film formed on said lower pixel electrode and said
thin film transistor, and of which an lower surface has a polarizer
formed thereon; an upper substrate of which an lower surface has an
upper pixel electrode composed of a transparent electrode and an
orientation film formed under said upper pixel electrode, and of
which an upper surface has a polarizer formed thereon; liquid
crystal injected between said lower substrate and said upper
substrate and varied in accordance with a voltage applied thereto
to selectively transmit light; and a driving circuit formed on the
upper surface of said lower substrate, for driving the polysilicon
thin film transistor in said pixel area.
[0021] A programmable mask according to another embodiment of the
present invention comprises a lower substrate of which an upper
surface has a polysilicon thin film transistor for switching a
pixel area in accordance with an electrical signal, a lower pixel
electrode composed of a transparent electrode and connected to the
drain electrode of said, thin film transistor, and an orientation
film formed on said lower pixel electrode and said thin film
transistor; an upper substrate of which an lower surface has an
upper pixel electrode composed of a transparent electrode and an
orientation film formed under said upper pixel electrode, and of
which an upper surface has a polarizer formed thereon; Guest-Host
liquid crystal injected between said lower substrate and said upper
substrate, for shielding or transmitting light by allowing the
oscillation direction of linearly-polarized light to be equal or
orthogonal to the light absorbing axis of a dye in accordance with
a voltage applied thereto; and a driving circuit formed on the
upper surface of said lower substrate, for driving the polysilicon
thin film transistor in said pixel area.
[0022] A programmable mask according to further another embodiment
of the present invention comprises a lower substrate of which an
upper surface has a polysilicon thin film transistor for switching
a pixel area in accordance with an electrical signal applied
thereto, a lower pixel electrode composed of a transparent
electrode and connected to the drain electrode of said thin film
transistor, a first dielectric mirror formed on said lower pixel
electrode for generating constructive interference of incident
light, and an orientation film formed on said first dielectric
mirror; an upper substrate of which lower surface has an upper
pixel electrode composed of a transparent electrode, a second
dielectric mirror formed on said upper pixel electrode for
generating constructive interference of incident light, and an
orientation film formed on said second dielectric mirror; and
liquid crystal injected between said lower substrate and said upper
substrate and varied in accordance with a voltage applied thereto
to selectively transmitting light, wherein said first dielectric
mirror and said second dielectric mirror forms a Febry-Parot type
optical filter, and only the constructive-interfered light having a
specific wavelength is selectively transmitted by said Febry-Parot
type optical filter.
[0023] A method for fabricating a biomolecule array using the
programmable mask according to the present invention comprises the
steps of preparing said programmable mask; providing a sample
substrate under said programmable mask; supplying a electrical
signal to said programmable mask to adjusting the transmission of
light in a selected pixel area by arrangement of the liquid
crystal; illuminating the light selectively passing through said
pixel area to said sample substrate; and generating optical
reaction in a biomolecule contained in said sample substrate by the
light illuminated thereto to form a biomolecule array according to
the pattern of said programmable mask.
[0024] In the method for fabricating the biomolecule array, the
light selectively passing through said pixel area may be changed to
non-polarized light by a depolarizer so that the non-polarized
light is illuminated to said sample substrate, and the optical
reaction may be generated by the non-polarized light to form the
biomolecule array.
[0025] In the method for fabricating the biomolecule array, said
liquid crystal includes nematic liquid crystal and dye added
thereto, and is Guest-Host liquid crystal which can shield or
transmit light by allowing the oscillation direction of
linearly-polarized light to be equal or orthogonal to the light
absorbing axis of the dye in accordance with a voltage applied
thereto, the arranged state of said Guest-Host liquid crystal may
be adjusted by the electrical signal applied to said programmable
mask to selectively irradiate the light to said sample substrate
such that the biomolecule array is formed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1a is a plan view of a TFT-LCD (Thin Film
Transistor-Liquid Crystal Display) type programmable mask according
to the present invention, and FIG. 1b is an elevational view
thereof.
[0027] FIG. 2 is a schematic view for illustrating a
photolithography operation using the TFT-LCD type programmable mask
according to the present invention.
[0028] FIG. 3 is a circuit diagram of an active matrix programmable
mask with a built-in driving circuit.
[0029] FIG. 4 is a section view of the active matrix programmable
mask with the built-in driving circuit according to one embodiment
of the present invention.
[0030] FIG. 5 is a section view of the active matrix programmable
mask with the built-in driving circuit, having a depolarizer.
[0031] FIG. 6 is a section view for illustrating the active matrix
programmable mask with the built-in driving circuit according to
another embodiment of the present invention.
[0032] FIG. 7 is a section view for illustrating the active matrix
programmable mask with a built-in driving circuit according to
further another embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0033] Hereinafter, the preferred embodiments of the present
invention will be explained with reference to the accompanying
drawings. However, these embodiments are provided so that those
skilled in the art can understand the present invention and it may
be variously changed, and the present invention should not be
understood as limited to the specific embodiments thereof. In
figure, the same reference numeral indicates the same element.
[0034] Next, the structure of a LCD type programmable mask for
switching the ultraviolet light and a method for manufacturing the
same will be described. The structure of the LCD type programmable
mask is schematically described with reference to the accompanying
drawings, and a circuit diagram of the programmable mask, a
sectional view of the programmable mask, the operation of the
optical valve liquid crystal, and light intensity adjustment and
wavelength filter function and non-polarization of the light
passing through the programmable mask are described. In order to
make understand the programmable mask, a method for manufacturing
the panel of the polysilicon thin film transistor of the TFT-LCD
type programmable mask, a method for forming a pixel, a method for
injecting liquid crystal, and a method for attaching the upper and
lower panels each other are described.
[0035] FIG. 1a is a plan view for illustrating the TFT-LCD type
programmable mask according to the present invention, and FIG. 1b
is an elevational view thereof.
[0036] Referring FIGS. 1a and 1b, the schematic structure of the
TFT-LCD type programmable mask as follows. A quartz substrate 100
which has excellent transmissivity of the ultraviolet light has a
rectangular shape like a general photomask, and a portion thereof
is formed with a TFT-LCD type optical valve area, i.e., an
ultraviolet-light-illuminated area 140 composed of an active matrix
polysilicon thin film transistor array and liquid crystal. Also,
the quartz substrate includes an area located at two sides of the
area 140 for applying electrical signals to the gate lines of the
transistors and data lines arranged in a matrix, respectively, a
area for selecting the pixel to be switched (applying a gate signal
and a source signal to the transistor of the pixel to be selected),
an driving circuit (an integrated circuit) area 150 formed on the
same plane simultaneously in the process the active matrix
transistor is manufactured, and an electrode pad 152 for connecting
the driving circuit with an external integrated circuit. A flexible
printed circuit is bonded to the electrode pad 152. In addition,
the outside of the quartz substrate 100 of the programmable mask
including the polysilicon thin film transistor is formed with
aligning keys 158 at four points. The quartz substrate 100 having
the above-mentioned structure is referred as a lower substrate
100a. As mentioned above, when the lower substrate 100a composed of
the driving circuit including the polysilicon thin film transistor
and the electrode pad 152 is formed, an upper substrate 100b which
is the opposite substrate thereof for injecting the liquid crystal
and is formed with pixels corresponding to the pixels on the lower
substrate 100a respectively is manufactured. The lower substrate
100a has a thickness of 2-5 mm so as to endure the bending due to
external force as the main body of the mask, and the upper
substrate 100b has a thickness of 0.1-0.6 mm such that the
absorption of the ultraviolet light can be minimized. In order to
maintain a certain interval therebetween, an adhesive portion 154
is formed between the lower substrate 100a and the upper substrate
100b, the liquid crystal is injected between the lower substrate
100a and the upper substrate 100b through a liquid injecting hole
156, and then the substrates are sealed. Like this, the lower
substrate 100a and the upper substrate 100b are attached each
other, and the liquid crystal is injected therebetween, and then
the substrates are sealed, thereby the programmable mask 100'
according to the present invention can be manufactured.
[0037] FIG. 2 is a schematic view for illustrating a
photolithography operation performed by illuminating the
ultraviolet light to the programmable mask and the sample
substrate. FIG. 2 illustrates the photolithography operation
performed in case where is applied to a device such as a contact
type mask aligner.
[0038] Referring to FIG. 2, generally, the mask having a patterned
chromium on the quartz substrate is used as the mask, but the
present invention uses the programmable mask 100' in which the
lower substrate 100a and the upper substrate 100b are attached each
other shown in FIGS. 1a and 1b. This mask 100' is laid on a support
base 170, and the sample substrate 176 to be formed with the
biomolecule or macromolecule is positioned below the programmable
mask 100', and the programmable mask 100' and the sample substrate
176 are fixed such that the aligning keys thereof are matched each
other, and then data programmed in a personal computer 174 are
supplied through a connecting portion 172 to operate a desired
transistor on the matrix such that the liquid crystal is switched.
The pattern 178 shown in FIG. 2 is the pattern of the biomolecule
or macromolecule synthesized by repeatedly illuminating the
ultraviolet light 111.
[0039] FIG. 3 is a circuit diagram of the programmable mask with a
built-in driving circuit, having a polysilicon drive integrated
circuit therein, according to the preferred embodiment of the
present invention.
[0040] Referring to FIG. 3, the programmable mask according to the
present invention is characterized in that it is integrated with
the driving circuit, because it has a purpose for synthesizing the
DNA of the high density, and the polysilicon thin film transistor
is arranged in the pixel portion. In FIG. 3, the array of the high
density can be formed by providing the built-in driving circuit
composed of the polysilicon thin film transistor at the periphery
of the pixel area. Such active matrix programmable mask with the
built-in driving circuit has the merit that the ultraviolet light
can be precisely adjusted and the high density can be accomplished.
The programmable mask according to the present invention has the
polysilicon thin film transistor formed in the pixel area and the
built-in driving circuit formed simultaneously in the process for
manufacturing the pixel at the periphery of the pixel area. In
order to directly connect the circuit to the gate line 106 and the
data line 110, the pixel area and the driving circuit whose the
active layer of the transistor is formed of the polysilicon are
formed in the same plane. In order to stably driving the liquid
crystal, a storage electrode having a wide area for maximizing the
capacitance of the above-mentioned electrode of a commercial
TFT-LCD is formed in the pixel area.
[0041] FIG. 4 is a section view of the active matrix programmable
mask with the built-in driving circuit according to the one
embodiment of the present invention.
[0042] Referring to FIG. 4, the fabricating method thereof will be
explained. A polysilicon thin film 102 is formed on a quartz
substrate 100 having a thickness of 2-5 mm by an excimer laser
annealing method or a furnace annealing method, and then a gate
insulating film 104 is formed by a PECVD (Plasma Enhanced Chemical
Vapor Deposition) or a high-temperature oxidation method.
Thereafter, a gate electrode 106 composed of a doped polysilicon or
metal is formed thereon. After an interlayer insulating film 108 is
deposited and a source electrode 110 and a drain electrode 112 are
formed, a lower pixel electrode 117 composed of the transparent
electrode such as ITO (Indium Tin Oxide) and connected with the
drain electrode 112 is formed. And, an orientation film 116 for
allowing the liquid crystal to be oriented is formed. The
above-mentioned process is the method for manufacturing the lower
substrate 100a. The method for manufacturing the upper substrate
100b is progressed as follows. A shielding film 118 for shielding
the ultraviolet light illuminated to the thin film transistor is
formed on a quartz substrate 100 having a thickness of 100-600
.mu.m and a protecting film (not shown) is formed, and then an
orientation film 116 and an upper pixel electrode 119 composed of a
transparent electrode and applied with a common voltage are formed
under the protection film. The upper substrate 100b and the lower
substrate 100a manufactured as mentioned above are attached each
other in the order of the general TFT-LCD process. After the
attachment process thereof is finished, a polarizer 120a and a
polarizer 120b orthogonal to the polarizer 120a are attached to the
substrates 100a and 100b. FIGS. 4(a) and 4(c) show the state that
the polarized light 111a is output through the liquid crystal 122
when a ground voltage (0 V) is applied to the upper and lower end
of the liquid crystal 122. At this time, the ultraviolet light 111
rotated by 90 degree passes through the liquid crystal 122. FIG.
4(b) shows the state that the linearly-polarized ultraviolet light
output through the upper polarizer 120a is shielded in the lower
polarizer 102b when a source voltage is applied to the transparent
electrode 117 according to an operation of the polysilicon thin
film transistor. At this time, the linearly-polarized ultraviolet
light is not rotated in the liquid crystal, so that the direction
of the linearly-polarized light is maintained. By combining one
polysilicon thin film transistor and one liquid pixel shown in FIG.
4, the dense programmable mask having a size of 10-20 .mu.m can be
fabricated.
[0043] The polarizers 120a and 120b can be implemented by using a
macromolecule film having a transmissivity and a tolerance with
respect to the ultraviolet light, i.e., an organic polymer
substance, and an inorganic crystal having birefringence
characteristics. As the representative organic polymer, there is
polyvinyl alcohol (PVA), and, as the inorganic crystal, there are
calcite, quartz, tourmaline, sodium nitrate, rutile, and TiO.sub.2.
Concretely, a linear polarizer using the organic polymer dealt in
Newport corporation (Model No. 20LP-UV) and a Glan-Thomson calcite
polarizer composed of the inorganic crystal (Model NO. 10GT04).
[0044] As the orientation film 116, a substance of which a
transmissivity for ultraviolet light having the wavelength of
330-400 nm is high and deactivation is not generated is used. For
example, as the orientation 116, an ultraviolet-resistant polyimid
film, a silicon oxide film formed by a slope sputtering method or a
slope thermal deposition method, or a DLC (Diamond-like-carbon)
film for allowing the liquid crystal to be oriented by illuminating
an ion beam can be used.
[0045] FIG. 5 shows a case where a depolarizer for removing the
polarized property 124 is attached under the polarizer 120b.
[0046] Referring to FIG. 5, the light 111a passing through the
depolarizer 124 is similar to the incident light 111, except for
the intensity of light. By further comprising the depolarizer 124,
the non-polarized light is illuminated to the sample substrate (see
`176` in FIG. 2) to generate the optical reaction, thereby the
biomolecule or macromolecule array can be fabricated.
[0047] FIG. 6 is a section view for illustrating the active matrix
programmable mask with the built-in driving circuit according to
another embodiment of the present invention.
[0048] Referring to FIG. 6, the programmable mask shown in FIG. 6
switches the light in the method different from that of the
programmable mask shown in FIG. 4. That is, in FIG. 4, the two
polarizers 120a and 120b can be used, but, in FIG. 6, one polarizer
120a is used and Guest-Host type liquid crystals 130a, 130b are
used as the liquid crystal. While the general liquid crystal (see
`122` in FIG. 4) allows the incident polarized light to pass
therethrough, rotating the direction thereof or not, the Guest-Host
type liquid crystals 130a, 130b itself shields the light. The
ultraviolet light 111 is strongly absorbed to dichroic dye 130b. If
the voltage is not applied to the Guest-Host type liquid crystals
130a, 130b (FIG. 6(b)), because the oscillating direction of the
linearly-polarized light from the polarizer 120a is equal to the
light absorbing axis of the dye 130b, the light is absorbed so that
the transmitted light is dyed, thereby the ultraviolet light 111 is
strongly absorbed to the dye 130b so as to do not transmit the
programmable mask. Otherwise, if the voltage is applied to the
Guest-Host type liquid crystals 130a, 130b (FIGS. 6(a) and 6(c)),
because the oscillating direction of the linearly-polarized light
from the polarizer 120a is orthogonal to the light absorbing axis,
the light is not absorbed in principle so that the transmitted
light is not dyed, thereby the ultraviolet light 111 is hardly
absorbed to transmit the programmable mask. Regardless of the
number of the wavelengths of the incident ultraviolet light 111,
the wavelength of the ultraviolet light 11a passing through the
mask is equal to that of the incident ultraviolet light 111. That
is, no variation is generated, except for the intensity of the
light.
[0049] If only the light having a specific wavelength must be used
when the biomolecule or macromolecule array is fabricated, the
incident ultraviolet generating device according to the embodiment
of the present invention must be provided with a fine adjustable
optical filter under the ultraviolet light source and an
ultraviolet laser source must be used. If the optical filter is
used, it is troublesome when the ultraviolet light having a
plurality of wavelengths is needed. If the ultraviolet laser source
is used, the device for fabricating the array is limited, because
almost ultraviolet laser source has a pulse shape. Accordingly, in
the present invention, a Fabry-Parot type wavelength-variable
liquid crystal filter for transmitting only the light having the
needed wavelength among the light having a plurality of the
wavelengths is arranged on the mask in matrix. The basic principle
of the Fabry-Parot type filter using the liquid crystal is to
transmit only the constructive-interfered light by the variation of
n or d in the condition that the light repeatedly reflected between
the dielectric mirrors is constructive-interfered, that is, an
equation ndcos .theta.=m .lamda./2 (n=refractive index, d=thickness
of the liquid crsytal). Since the thickness of the liquid crystal
is fixed, the liquid crystal filter can transmit only the light
having a desired wavelength by the variation of the reflective
index n. The variation of n can be actually adjusted by the
variation of the voltage across the both ends of the liquid
crystal. This type of the filter is constructed by arranging a
wavelength division multiplexing liquid crystal filter on the
programmable mask so as to be driven by the polysilicon transistor,
in the optical communication system.
[0050] FIG. 7 is a section view for illustrating the active matrix
programmable mask with the built-in driving circuit according to
further another embodiment of the present invention.
[0051] Referring to FIG. 7, the programmable mask includes a
Fabry-Parot wavelength-variable liquid crystal filter, and is
different from the structure in FIGS. 4 to 6 in that the dielectric
mirrors 126 are located on the both ends of the liquid crystal. The
other words, the dielectric mirror 126 for generating the
constructive interference of the incident ultraviolet light are
provided on the lower pixel electrode 117 composed of the
transparent electrode and connected with the drain electrode 112 of
the polysilicon thin film transistor in the lower substrate 100a,
and the orientation film 116 is provided on the dielectric mirror
126. Also, the dielectric mirror 126 for generating the
constructive interference of the incident ultraviolet light is
provided under the upper pixel electrode 119 composed of the
transparent electrode and applied with the common voltage in the
upper substrate 100b, and the orientation film 116 is provided
under the dielectric film 126. The thickness of the liquid crystal
and the reflectivity of the dielectric mirror 126 selected thereat
is determined by calculation. Since the light having the wavelength
selected thereat is in the linearly-polarized state, it can be
changed to the non-polarized light by the above-mentioned
depolarizer (see `124` in FIG. 5).
[0052] As mentioned above, according to the present invention, the
programmable mask includes a LCD panel in which the color filter
layer is removed and the depolarizer and the transmission of the
non-polarized ultraviolet light is adjusted, thereby the
biomolecule or macromolecule array such as DNA can be effectively
fabricated.
[0053] According to the present invention, the volume of the device
can be reduced in comparison with the existing optical mask or
micromirror array and the inexpensive array of high density can be
readily fabricated. Also, mass production of the biomolecule or
macromolecule array can be readily performed in case where a
stepping function exists or many an array pattern exist in a
programmable mask.
[0054] Since the liquid crystal, the orientation film, the
substrate, and the polarizer which allows the ultraviolet light to
pass therethrough and is not deactivated by the ultraviolet light
are used, the programmable mask can be used for a long time. In
addition, if which the polysilicon thin film transistor is used
instead of the amorphous silicon, it can be used for a longer time,
because the stability for dispersion of the light becomes high.
[0055] In case where the LCD with a built-in driving circuit is
used, the dense biomolecule or macromolecule array in which the
size of the cell is small can be fabricated. Because the
photolithography condition can be readily adjusted by adjusting the
intensity or the wavelength of the light passing through the
programmable mask, the biomolecule or macromolecule array of high
yield can be fabricated.
[0056] Also, in case where such programmable mask is fabricated in
a small size, it is can be utilized as a DNA chip manufacturing
device which can be used in a hospital or a laboratory.
Accordingly, the DNA chip of high density can be inexpensively
fabricated.
* * * * *