U.S. patent application number 12/883185 was filed with the patent office on 2011-01-06 for dielectric layer.
This patent application is currently assigned to INDUSTRIAL TECHNOLOGY RESEARCH INSTITUTE. Invention is credited to Liang-Xiang Chen, Tarng-Shiang Hu, Pang LIN, Wei-Ling Lin.
Application Number | 20110001221 12/883185 |
Document ID | / |
Family ID | 38285850 |
Filed Date | 2011-01-06 |
United States Patent
Application |
20110001221 |
Kind Code |
A1 |
Lin; Wei-Ling ; et
al. |
January 6, 2011 |
DIELECTRIC LAYER
Abstract
A dielectric layer is provided. The dielectric layer includes a
photo-sensitive polymer or a non-photo-sensitive polymer and an
amorphous metal oxide disposed in the photo-sensitive polymer or a
non-photo-sensitive polymer.
Inventors: |
Lin; Wei-Ling; (Nantou
County, TW) ; LIN; Pang; (Hsinchu City, TW) ;
Hu; Tarng-Shiang; (Hsinchu City, TW) ; Chen;
Liang-Xiang; (Taichung City, TW) |
Correspondence
Address: |
JIANQ CHYUN INTELLECTUAL PROPERTY OFFICE
7 FLOOR-1, NO. 100, ROOSEVELT ROAD, SECTION 2
TAIPEI
100
TW
|
Assignee: |
INDUSTRIAL TECHNOLOGY RESEARCH
INSTITUTE
Hsinchu
TW
|
Family ID: |
38285850 |
Appl. No.: |
12/883185 |
Filed: |
September 16, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11308387 |
Mar 21, 2006 |
7829137 |
|
|
12883185 |
|
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Current U.S.
Class: |
257/632 ;
257/E23.001 |
Current CPC
Class: |
H01L 51/0537 20130101;
C23C 24/08 20130101; H01L 21/02183 20130101; H01L 29/517 20130101;
H01L 21/28158 20130101; H01L 21/316 20130101; H01L 21/02282
20130101 |
Class at
Publication: |
257/632 ;
257/E23.001 |
International
Class: |
H01L 23/58 20060101
H01L023/58 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 20, 2006 |
TW |
95102236 |
Claims
1. A dielectric layer, comprising: a photo-sensitive polymer or a
non-photo-sensitive polymer; and an amorphous metal oxide, disposed
in the photo-sensitive polymer or a non-photo-sensitive
polymer.
2. The dielectric layer of claim 1, wherein the amorphous metal
oxide comprises metal oxide, and the metal of the metal oxide
includes Al, Ti, Zr, Ta, Si, Ba, Ge or Hf.
3. The dielectric layer of claim 1, wherein the photo-sensitive
polymer or the non-photo-sensitive polymer comprising polyimide,
polyamide, polyvinylalcohol, polyvinylphenol, polyacrylate, epoxy,
polyurethane, fluoropolymer, polysiloxane, polyester,
polyacrylonitrile, polystyrene, or polyethylene.
4. The dielectric layer of claim 1, wherein a dielectric constant
of the dielectric layer is about 5.7.
5. The dielectric layer of claim 1, wherein a dielectric constant
of the dielectric layer is about 6.7.
6. The dielectric layer of claim 1, wherein the dielectric layer is
a gate dielectric layer of a transistor.
7. The dielectric layer of claim 6, wherein a mobility .mu. and an
on/off ratio of the transistor are 0.047 cm.sup.2/Vs and
10.sup.4-10.sup.5 respectively.
8. The dielectric layer of claim 6, wherein a mobility .mu. and an
on/off ratio of the transistor are 0.059 cm.sup.2/Vs and 10.sup.4
respectively.
9. The dielectric layer of claim 6, wherein the transistor is a
field effect transistor.
10. The dielectric layer of claim 6, wherein the transistor is a
thin film transistor.
11. The dielectric layer of claim 1, wherein the dielectric layer
is a dielectric layer of a capacitor.
12. The dielectric layer of claim 1, wherein the dielectric layer
is applied in high frequency devices.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional application of and claims
the priority benefit of an application Ser. No. 11/308,387, filed
on Mar. 21, 2006, which claims the priority benefit of Taiwan
application serial no. 95102236, filed on Jan. 20, 2006. The
entirety of each of the above-mentioned patent applications is
hereby incorporated by reference herein and made a part of this
specification.
BACKGROUND OF THE INVENTION
[0002] 1. Field of Invention
[0003] The present invention relates to a composition, material
layer and method for forming the same used in field effect
transistor (FET). More particularly, the present invention relates
to a composition and a dielectric layer formed by the same and
method for forming the dielectric layer.
[0004] 2. Description of Related Art
[0005] For the semiconductor carrier transmission of the field
effect transistor, a voltage is applied to the gate, and sufficient
induced charges are formed at the interface between the
semiconductor and the gate dielectric layer so as to promote the
carrier transmission. In order to that the FET has a high current
I.sub.D in low voltage operation, capacitance is also involved in
addition to the carrier mobility and the channel length between the
source and drain electrodes. The thinner the thickness of the film
of the dielectric layer is and the higher the dielectric constant
is, and the higher the capacitance is.
[0006] 3M company provides a dielectric layer with high dielectric
constant in U.S. Pat. No. 6,586,791, wherein the gate dielectric
layer is formed by coating the suspended solution formed by mixing
the nanometer ceramic powder into polymer material. However,
stripes may be formed on the surface of the dielectric layer made
by the method, and therefore, the roughness of the surface is
worse, so that leakage path is easily formed to generate a high
leakage current.
SUMMARY OF THE INVENTION
[0007] Accordingly, the present invention is to provide a
dielectric layer having high dielectric constant, low leakage
current, high uniformity, and high surface roughness.
[0008] The present invention provides a dielectric layer. The
dielectric layer includes a photo-sensitive polymer or a
non-photo-sensitive polymer and an amorphous metal oxide in the
photo-sensitive polymer or the non-photo-sensitive polymer.
[0009] According to the embodiment of the present invention, the
amorphous metal oxide includes metal oxide, and the metal includes
Al, Ti, Zr, Ta, Si, Ba, Ge or Hf. The photo-sensitive polymer or
non-photo-sensitive polymer includes polyimide, polyamide,
polyvinylalcohol, polyvinylphenol, polyacrylate, epoxy,
polyurethane, fluoropolymer, polysiloxane, polyester,
polyacrylonitrile, polystyrene, or polyethylene. The dielectric
layer can be used as a gate dielectric layer of a field effect
transistor and a thin film transistor or the dielectric layer of a
capacitor, or the dielectric layer can be applied in high frequency
devices.
[0010] The dielectric layer of the present invention comprises the
photo-sensitive polymer or the non-photo-sensitive polymer and the
amorphous metal oxide formed therein. The metal oxide is at
amorphous phase, rather than crystal phrase, and the dielectric
constant is high, so that the metal oxide can improve the entire
dielectric constant of the dielectric layer. In addition, as the
metal oxide is formed by baking the homogeneous phase composition,
compared to the dielectric layer made by the suspended solution
formed by mixing the crystal metal oxide powder into polymer, the
film uniformity of the composition of the present invention is
better, and the metal oxide is arranged in the formed composition
with better uniformity, and the composition also has better solvent
resistance. Therefore, the dielectric layer of the present
invention can be applied in the gate dielectric layers of a field
effect transistors and a thin film transistor, the dielectric layer
between the two electrodes in the capacitor, and even applied in
the high frequency devices, and the formed device has features such
as high breakdown voltage, high aperture rate and low power
consumption.
[0011] In addition, since the dielectric layer can be formed in low
temperature, the dielectric layer can be applied in flexible
substrate.
[0012] In order to the make the aforementioned and other objects,
features and advantages of the present invention comprehensible, a
preferred embodiment accompanied with figures is described in
detail below.
[0013] 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
[0014] The accompanying drawings are included to provide a further
understanding of the invention, and are incorporated in and
constitute a part of this specification. The drawings illustrate
embodiments of the invention and, together with the description,
serve to explain the principles of the invention.
[0015] FIG. 1 is a schematic diagram of the transistor with top
contact structure according to the present invention.
[0016] FIG. 2 is a schematic diagram of the transistor with bottom
contact structure according to the present invention.
DESCRIPTION OF EMBODIMENTS
[0017] The dielectric layer of the present invention is formed by
baking a liquid composition. The liquid composition includes a
photo-sensitive polymer or a non-photo-sensitive polymer, an
organometallic compound and a solvent. The photo-sensitive polymer
or non-photo-sensitive polymer includes polyimide, polyamide,
polyvinylalcohol, polyvinylphenol, polyacrylate, epoxy,
polyurethane, fluoropolymer, polysiloxane, polyester,
polyacrylonitrile, polystyrene, or polyethylene.
[0018] The organometallic compound is a liquid metal alkoxide, and
the structure is:
M(OR).sub.n
wherein, M includes Al, Ti, Zr, Ta, Si, Ba, Ge and Hf; OR is an
alkoxy with 1-10 carbons, such as methoxy, ethoxy, propoxy,
isopropoxy, butoxy, isobutoxy, pentyloxy, hexyloxy, heptyloxy,
octyloxy, nonyloxy, decyloxy, 2-methyl-nonyloxy, 3-methyl-nonyloxy,
4-methyl-nonyloxy, 5-methyl-nonyloxy, 3-ethyl-octyloxy,
4-ethyl-octyloxy, 4-propyl-heptyloxy, 4-isopropyl-heptyloxy,
2-methyl-octyloxy, 3 -methyl-octyloxy, 4-methyl-octyloxy, 3
-ethyl-heptyloxy, 4-ethyl-heptyloxy, 2-methyl-heptyloxy,
3-methyl-heptyloxy, 4-methyl-heptyloxy, 3-ethyl-hexyloxy,
2-methyl-hexyloxy, 3-methyl-hexyloxy, 3-ethyl-pentyloxy,
2-methyl-pentyloxy, 3-methyl-pentyloxy, 2-methyl-propoxy,
2-methoxy-3-ethoxy, etc.; and n is 1-5.
[0019] When the organometallic compound is an aluminum alkoxide,
the embodiment thereof includes
Al(OCH.sub.2CH.sub.2OCH.sub.3).sub.3. When the organometallic
compound is a titanium alkoxide, the embodiment thereof includes
Ti(OC.sub.4H.sub.9).sub.4. When the organometallic compound is a
zirconium alkoxide, the embodiment thereof includes
Zr(OC.sub.8H.sub.17).sub.4. When the organometallic compound is a
tantalum alkoxide, the embodiment thereof includes
Ta(OC.sub.2H.sub.5).sub.5. When the organometallic compound is a
silicon alkoxide, the embodiment thereof includes
Si(OCH.sub.3).sub.4. When the organometallic compound is a barium
alkoxide, the embodiment thereof includes
Ba(OC.sub.4H.sub.9).sub.2. When the organometallic compound is a
hafnium alkoxide, the embodiment thereof includes
Hf(OC.sub.8H.sub.17).sub.4. When the organometallic compound is a
germanium alkoxide, the embodiment thereof includes
Ge(OC.sub.2H.sub.5).sub.4.
[0020] The solvent in the composition of the present invention is
used to dissolve the photo-sensitive polymer or non-photo-sensitive
polymer to form a homogeneous phase liquid with the organometallic
compound. The solvent includes, for example, water, methanol,
ethanol, isopropanol, butanol, tetrahydrofuran, formamide,
N-methylpyrrolidone (NMP), N,N-dimethylacetamide (DMAc),
N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO),
r-butyrolactone, 1,3-dimethyl-2-imidazolidinone (DMI).
[0021] The composition of the present invention can be used to form
the gate dielectric layer of the transistor, and the following will
describe the composition through the embodiment.
[0022] FIG. 1 is a schematic diagram of the transistor with top
contact structure according to the present invention. FIG. 2 is a
schematic diagram of the transistor with bottom contact structure
according to the present invention.
[0023] Referring to FIG. 1 and FIG. 2, a gate 102 is formed on a
substrate 100. Then, the composition of the present invention is
formed on the electrode 102. The substrate 100 is, for example, a
rigid substrate such as glass substrate or silicon wafer, or a
flexible substrate. The material of the gate 102 is, for example,
indium tin oxide (ITO). Then, a hard baking process and a soft
baking process are performed in sequence to remove the solvent in
the composition, so that the metal in the organometallic compound
convert to metal oxide so as to form the gate dielectric layer
104.
[0024] The composition of the present invention can be formed on
the substrate 100 using direct patterning. Alternatively, the
composition can be first coated on the substrate 100, and a
patterning process is performed after the baking process. The
method of direct patterning includes, for example, slot die
coating, flexographic coating, inkjet printing, microcontact
printing, nanoimprinting, and screen printing. The method of
coating includes, for example, spin coating, dip coating, and
spray. The method of patterning includes, for example,
photolithography, etching, and laser ablation. The baking process
includes a soft baking process in low temperature and a hard baking
process in higher temperature. The temperatures of the soft baking
process and the hard baking process are related to the kind of the
solvent in the composition. The temperature of soft baking process
may be 0.degree. C.-150.degree. C., and the preferred is room
temperature--100.degree. C., and the more preferred is room
temperature--80.degree. C. The temperature of hard baking process
may be 0.degree. C.-300.degree. C., and the preferred is room
temperature--200.degree. C., and the more preferred is room
temperature--150.degree. C.
[0025] Next, a patterned semiconducting layer 106, a source 108 and
a drain 110 are formed, so as to complete the transistor with the
top contact structure as shown in FIG. 1, or the transistor with
the bottom contact structure as shown in FIG. 2.
[0026] The composition of the present invention can be used to
fabricate the gate dielectric layer of the field effect transistor
and the thin film transistor and can also be used to fabricate the
dielectric layer of a capacitor, or the composition of the present
invention can also be applied in high frequency devices.
The First Embodiment
[0027] Referring to FIG. 1, the composition, formed by mixing the
20 wt. % Ta(OC.sub.2H.sub.5).sub.4, 6 wt. % polyimide and
N-methylpyrrolidone (NMP) or r-butyrolactone, is spin coated on the
glass substrate with bottom electrode of ITO thereon by speed of
400 rpm/10 s and 1000 rpm/30 s, so as to form a thin film. Next,
the thin film is performed a soft baking process on the hart plate
at 80.degree. C., then, the thin film is performed a hard baking
process in an oven at 150.degree. C. to form a gate dielectric
layer. Thereafter, a patterned semiconducting layer, a source and a
drain are formed, so as to complete a transistor with top contact
structure. Thereafter, I-V and C-V characteristics of the
transistor are measured. The dielectric constant is 5.7. The
mobility is 0.047 cm.sup.2/Vs. The on/off ratio is
10.sup.4-10.sup.5.
The Second Embodiment
[0028] The transistor with top contact structure is formed
according to the aforementioned method, besides, the composition is
changed to the compound formed by 30 wt. % Ta.sub.2(acac).sub.5, 6
wt. % polyimide and N-methylpyrrolidone (NMP) or r-butyrolactone.
I-V and C-V characteristics of the transistor are measured. The
dielectric constant is 6.7. The mobility .mu. is 0.059 cm.sup.2/Vs.
The on/off ratio is 10.sup.4.
[0029] The organometallic compound in the aforementioned
composition is described by the example of tantalum alkoxide. The
other metal alkoxide of the present invention can also form the
composition using the methods similar to the first or second
embodiment, wherein the metal includes Al, Ti, Zr, Ta, Si, Ba, Ge
or Hf, and, after baking the formed composition, the dielectric
layer can be formed.
[0030] 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.
* * * * *