THIN FILM TRANSISTOR ARRAY PANEL AND METHOD FOR MANUFACTURING THE SAME
20170053940 ยท 2017-02-23
Inventors
- Zhu Xun (Suwon-si, KR)
- Jae Woo Park (Seongnam-si, KR)
- Jae Won SONG (Seoul, KR)
- KEUM HEE LEE (GOYANG-S1, KR)
- JUNE WHAN CHOI (HWASEONG-S1, KR)
Cpc classification
G02F1/1368
PHYSICS
H01L21/76852
ELECTRICITY
H10D30/0316
ELECTRICITY
H01L2924/0002
ELECTRICITY
H10D30/6713
ELECTRICITY
H10D86/423
ELECTRICITY
H01L23/53238
ELECTRICITY
H01L2924/00
ELECTRICITY
H01L2924/0002
ELECTRICITY
H10D30/0321
ELECTRICITY
H10D86/0221
ELECTRICITY
H01L2924/00
ELECTRICITY
International classification
Abstract
A thin film transistor array panel is provided as follows. A gate electrode is disposed on a substrate. A semiconductor layer is disposed on the gate electrode. A gate insulating layer is disposed between the gate electrode and the semiconductor layer. A source electrode is disposed on a first side of the semiconductor layer, having a first lateral surface. A drain electrode is disposed on a second side of the semiconductor layer, having a second lateral surface. The first and second lateral surfaces define a spacing which overlaps the gate electrode. A metal suicide layer is disposed on the first and second lateral surfaces. A passivation layer is disposed on the metal silicide layer, the source electrode and the drain electrode. The passivation layer is not in contact with the first and second lateral surfaces.
Claims
1. A method of manufacturing a thin film transistor array panel, comprising: forming a gate electrode on a substrate; forming a semiconductor layer on the substrate and the gate electrode; forming a gate insulating layer between the gate electrode and the semiconductor layer; forming source and drain electrodes disposed on first and second sides of the semiconductor layer, respectively, wherein the source and drain electrodes include a metal element; forming a silane (SiH.sub.4) material layer on the source and drain electrodes; and forming a passivation layer on the source and drain electrodes, wherein the forming of the passivation layer causes a silicidation process wherein the silicidation process comprises a reaction between silicon of the silane (SiH.sub.4) material layer and the metal element of the source and drain electrodes thereby forming a metal silicide layer on first and second lateral sides of the source and drain electrodes, respectively, wherein the first and second lateral sides define a spacing that overlaps the gate electrode, wherein the first and second lateral sides are in contact with the metal silicide layer without being in contact with the passivation layer.
2. The method of claim 1, wherein the forming of the silane (SiH.sub.4) material layer is performed by a chemical vapor deposition process.
3. The method of claim 2, wherein the passivation layer is formed by a reaction of SiH.sub.4 and NO.sub.2.
4. The method of claim 3, wherein the passivation layer is in contact with the semiconductor layer through the spacing defined by the first and second lateral surfaces of the source and drain electrodes.
5. The method of claim 4, wherein the forming of the source electrode includes forming a barrier layer on the semiconductor layer and forming a main wiring layer on the barrier layer, and the main wiring layer includes copper or a copper alloy and the barrier layer includes a metal oxide.
6. The method of claim 5, wherein the forming of the passivation layer includes forming a lower passivation layer and forming an upper passivation layer, wherein the forming of the lower passivation layer causes the silicidation process to occur at an interface between the main wiring layer and the silane (SiH.sub.4) material layer, wherein the lower passivation layer includes silicon oxide, and the upper passivation layer includes silicon nitride.
7. The method of claim 6, wherein the metal suicide layer is further disposed on upper surfaces of the source and drain electrodes, wherein the upper surfaces of the source and drain electrodes are not in contact with the passivation layer.
8. The method of claim 5, further comprising forming a capping layer on an upper surface of the main wiring layer, wherein the upper surface of the main wiring layer is not in contact with the passivation layer.
9. The method of claim 1, wherein the semiconductor layer includes an oxide semiconductor.
10. The method of claim 1, wherein the forming of the semiconductor layer and the forming of the source and drain electrodes are performed by using a mask.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] These and other features of the present invention will become more apparent by describing exemplary embodiments thereof with reference to the accompanying drawings of which:
[0009]
[0010]
[0011]
[0012]
[0013]
[0014]
[0015]
[0016]
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0017] Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. However, the present invention may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, the thickness of layers and regions may be exaggerated for clarity. It will also be understood that when an element is referred to as being on another element or substrate, it may be directly on the other element or substrate, or intervening layers may also be present. It will also be understood that when an element is referred to as being coupled to or connected to another element, it may be directly coupled to or connected to the other element, or intervening elements may also be present. Like reference numerals may refer to the like elements throughout the specification and drawings.
[0018]
[0019] Referring to
[0020] The gate lines 121 transmit a gate signal and extend in a transverse direction. Each gate line 121 includes gate electrodes 124 protruding from the gate line 121.
[0021] The gate line 121 and the gate electrode 124 may have a dual-layer structure having first layers 121p and 124p and second layers 121q and 124q. Each of the first layers 121p and 124p and the second layers 121q and 124q may be formed of an aluminum-based metal such as aluminum (Al) and an aluminum alloy, a silver-based metal such as silver (Ag) and a silver alloy, a copper-based metal such as copper (Cu) and a copper alloy, a molybdenum-based metal such as molybdenum (Mo) and a molybdenum alloy, chromium (Cr), titanium (Ti), tantalum (Ta), manganese (Mn), or the like. For example, the first layers 121p and 124p may include titanium, and the second layers 121q and 124q may include copper or a copper alloy.
[0022] Alternatively, the first layers 121p and 124p and the second layers 121q and the 124q may be formed of a combination of films having different physical properties. The gate line 121 and the gate electrode 124 include two layers, but are not limited thereto, and may be formed as a single layer or three layers.
[0023] A gate insulating layer 140 formed of an insulating material such as a silicon oxide or a silicon nitride is positioned on the gate line 121. The gate insulating layer 140 may include a first insulating layer 140a and a second insulating layer 140b. The first insulating layer 140a may be formed of a silicon nitride (SiN.sub.x) with a thickness of about 4000 , and the second insulating layer may be formed of a silicon oxide (SiO.sub.x) with a thickness of about 500 . Alternatively, the first insulating layer 140a may be formed of a silicon oxynitride (SiON), and the second insulating layer 140b may be formed of a silicon oxide (SiO.sub.x). The gate insulating layers 140a and 140b include two layers, but may include a single layer.
[0024] Semiconductor layers 151 are formed on the gate insulating layer 140. The semiconductor layers 151 may be formed of amorphous silicon, crystalline silicon, or an oxide semiconductor. The semiconductor layers 151 extend primarily in a vertical direction and include projections 154 that protrude toward the gate electrode 124.
[0025] When the semiconductor layer 151 is formed of an oxide semiconductor, the semiconductor layer 151 contains at least one of zinc (Zn), indium (In), tin (Sn), gallium (Ga), and hafnium (Hf). For example, The semiconductor layer 151 may be an indium-gallium-zinc oxide.
[0026] Data lines 171, source electrodes 173 connected to the data lines 171, and drain electrodes 175 are formed on the semiconductor layer 151 and the gate insulating layer 140. The data lines 171 transfer data signals and extend primarily in the vertical direction to cross the gate lines 121. The source electrode 173 may extend from the data line 171. The source electrode 173 may overlap the gate electrode 124. The source electrode 173 may be substantially U-shaped.
[0027] The drain electrode 175 is separated from the data line 171 and extends upward from the center of the U shape of the source electrode 173.
[0028] The data line 171, the source electrode 173, and the drain electrode 175 have a dual-film structure of barrier layers 171p, 173p, and 175p and main wiring layers 171q, 173q, and 175q. The barrier layers 171p, 173p, and 175p are formed of a metal oxide and the main wiring layers 171q, 173q, and 175q are formed of copper or the copper alloy.
[0029] For example, the barrier layers 171p, 173p, and 175p may be formed of one of an indium-zinc oxide, a gallium-zinc oxide, and an aluminum-zinc oxide.
[0030] The barrier layers 171p, 173p, and 175p serve to prevent the material such as copper or the like from being diffused to the semiconductor layer 151.
[0031] A metal silicide layer 177 is positioned on the main wiring layers 171q, 173q, and 175q. The metal silicide layer 177 includes copper, silicon, and oxygen, and for example, may include a compound represented by CuSi.sub.xO.sub.y. The metal silicide layer 177, covering the source electrode 173 and the drain electrode 175, is in contact with the surface of the source electrode 173 and the drain electrode 175. For example, the metal silicide layer 177 covers exposed lateral surfaces A and B of the source electrode 173 and the drain electrode 175 and exposed upper surfaces of the source electrode 173 and the drain electrode 175. The metal silicide layer 177 is not in contact with the gate insulating layer 140.
[0032] Hereafter, the exposed later surface A of the source electrode 173 and the drain electrode 175 near the channel region of the semiconductor layer 151 will be described.
[0033] Referring to
[0034] One gate electrode 124, one source electrode 173, and one drain electrode 175 form one thin film transistor (TFT) along with the projection 154 of the oxide semiconductor layer 151, and the channel of the thin film transistor is formed in the projection 154 between the source electrode 173 and the drain electrode 175.
[0035] Lateral surfaces of the source electrode 173 and the drain electrode 175 adjacent to the channel region are exposed, and exposed lateral parts A of the source electrode 173 and the drain electrode 175 are covered by the metal silicide layer 177. If the lateral parts A of the source electrode 173 and the drain electrode 175 is exposed without the metal silicide layer 177, if a following process forming the passivation layer including a silicon oxide is performed or a heat treatment to provide a channel characteristic to the protrusion 154 of the semiconductor layer is performed, the material such as copper included in the main wiring layers 171q, 173q, and 175q forms an porous oxide such that the thin film transistor characteristic may be decreased.
[0036] Accordingly, the metal suicide layer may prevent the material such as copper or the like from being oxidized in performing subsequent processes such as forming the passivation layer and performing the heat treatment.
[0037] The metal suicide layer 177 may formed using two step processes including forming a silane material layer and performing a silicidation process using the silane material layer. Detailed descriptions will be made later with reference to
[0038] The passivation layer 180 may include a lower passivation layer 180a and an upper passivation layer 180b. The lower passivation layer 180a may be formed of a silicon oxide and the upper passivation layer 180b may be formed of a silicon nitride.
[0039] Since the semiconductor layer 151 includes an oxide semiconductor, the lower passivation layer 180a adjacent to the semiconductor layer 151 is formed of a silicon oxide. When the lower passivation layer 180a is formed of a silicon nitride, the semiconductor layer 151 does not serve as a channel region of a thin film transistor.
[0040] The passivation layer 180 be in contact with the exposed part that is not covered by the source electrode 173 and the drain electrode 175 between the source electrode 173 and the drain electrode 175.
[0041] Contact holes 185 that expose one end of the drain electrodes 175 are formed on the passivation layer 180. Pixel electrodes 191 are formed on the passivation layer 180. The pixel electrode 191 is physically and electrically connected with the drain electrode 175 through the contact hole 185, and is applied with data voltage from the drain electrode 175.
[0042] The pixel electrode 191 may be formed of a transparent conductor such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide).
[0043]
[0044] Referring to
[0045] For example, after the two layers is formed, a photoresist (not illustrated) is deposited and patterned, and thereafter, the first layers 121p and 124p and the second layers 121q and 124q are etched together by using the patterned photoresist (not illustrated) as a mask. In this case, as an etchant, one that can etch both the first layers 121p and 124p and the second layers 121q and 124q may be used.
[0046] Referring to
[0047] The oxide layer 150 may contain at least one of zinc (Zn), indium (In), tin (Sn), gallium (Ga), and hafnium (Hf), the metal oxide layer 170p may contain one of an indium-zinc oxide, a gallium-zinc oxide, and an aluminum-zinc oxide, and the metal layer 170q may contain copper or a copper alloy. A photoresist is formed and patterned to form a first photoresist pattern 50 thereon. The first photoresist pattern 50 has a thick first region 50a and a relatively thin second region 50b. A difference in thickness of the first photoresist pattern 50 may be formed by controlling the amount of irradiated light with a mask or by using a reflow method. When the amount of light is controlled, a slit pattern, a lattice pattern, or a semitransparent layer may be formed on the mask. The thin second region 50b corresponds to a position where the channel region of the thin film transistor is to be formed.
[0048] Referring to
[0049] If the metal oxide layer 170p and the metal layer 170q are etched, lateral surfaces of the metal oxide layer 170p and the metal layer 170q covered with the first photoresist pattern 50 are also etched by the etchant, and as a result, a boundary line of the first metal layer 170p and the second metal layer 170q is positioned inside regions
[0050] A, B, and C where the first photoresist pattern 50 is formed.
[0051] In this case, the etchant that etches the metal oxide layer 170p and the metal layer 170q does not etch the gate insulating layer 140 and the oxide layer 150.
[0052] Additionally, the oxide layer 150 is etched by using the first photoresist pattern 50 as the mask.
[0053] Referring to
[0054] Referring to
[0055] In this case, the metal oxide layer 170p and the metal layer 170q are patterned to form the data lines 171p and 171g, the source electrodes 173p and 173q, and the drain electrodes 175p and 175q having a two layered structure. Further, the oxide semiconductor layer 151 includes the projection 154. The projection 154 may serve as a channel region of a thin film transistor.
[0056] Using the photoresist patterns having different thicknesses, formed are the semiconductor layers 151 and 154, the barrier layers 171p, 173p, and 175p, the main wiring layers 171q, 173q, and 175q of the data line 171, the source electrode 173, and the drain electrode 175. Since the semiconductor layers 151 and 154, the data line 171, the source electrode 173, and the drain electrode 175 are formed using the photoresist patterns as an etch mask, edges of them are vertically aligned.
[0057] Next, referring to
[0058] Referring to
[0059] The silane material layer 176 is formed to cover the channel region and the gate insulating layer 140 as well as the surface of the source electrode 173 and the drain electrode 175.
[0060] Referring to
[0061] The contact hole 185 exposing a part of the drain electrode 175 is formed by patterning the passivation layer 180, and the pixel electrode 191 is formed on the passivation layer 180 to form the thin film transistor array panel of
[0062]
[0063] Referring to
[0064] Color filters 230 are also formed on the second substrate 210 and the light blocking member 220. The color filters 230 are disposed in a region surrounded by the light blocking member 220, and may be elongated along a column of the pixel electrodes 191. Each color filter 230 may express one of three primary colors such as red, green, and blue. However, the expressed colors are not limited to the three primary colors of red, green, and blue, and each color filter 230 may express one of cyan, magenta, yellow, or white-based colors.
[0065] The light blocking member 220 and the color filter 230 are formed on an opposed array panel 200 as described above, however at least one of the light blocking member 220 and the color filter 230 may be formed on the thin film transistor array panel 100.
[0066] An overcoat 250 is formed on the color filter 230 and the light blocking member 220. The overcoat 250 may be formed of the insulation material. The overcoat 250 may seal the color filter 230, and may also provide a flat surface. Alternatively, the overcoat 250 may be omitted.
[0067] A common electrode 270 is formed on the overcoat 250.
[0068] The pixel electrode 191 applied with the data voltage generates an electric field together with the common electrode 270 applied with common voltage to determine a direction of liquid crystal molecules 31 of a liquid crystal layer 3 between the two electrodes. The pixel electrode 191 and the common electrode 270 constitute a capacitor to maintain the applied voltage even after the thin film transistor is turned off.
[0069] The pixel electrode 191 overlaps with a storage electrode line (not illustrated) to constitute a storage capacitor, and as a result, voltage storing capability of a liquid crystal capacitor may be increased.
[0070] The description of the thin film transistor array panel 100 may be applied with the content of the exemplary embodiment described with reference to
[0071] The thin film transistor array panel according to an exemplary embodiment is not limited to a liquid crystal display, but may be applied to other display systems such as an organic light emitting device.
[0072]
[0073]
[0074]
[0075] Referring to
[0076] Except for the described difference, the content described in
[0077]
[0078] Referring to
[0079] Referring to
[0080] Referring to
[0081] Referring to
[0082] The contact hole 185 exposing a part of the drain electrode 175 is formed by patterning the passivation layer 180, and the pixel electrode 191 is formed on the passivation layer 180 to form the thin film transistor array panel of
[0083]
[0084] While the present invention has been shown and described with reference to exemplary embodiments thereof, it will be apparent to those of ordinary skill in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.