Thin-film transistor substrate and liquid crystal display

• US 6,649,936 B1
• Filed: 03/15/2000
• Issued: 11/18/2003
• Est. Priority Date: 03/16/1999
• Status: Expired due to Term

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Philips LCD Company Limited (LG Display Co., Ltd.)
• Inventors: Sasaki, Makoto, Chul, Jo Gyoo, Sung, Chae Gee, Arai, Kazuyuki
• Primary Examiner(s): Flynn, Nathan J.
• Assistant Examiner(s): Sefer, Ahmed N.
• Application Number:
  US09/526,150
• Time in Patent Office: 1,343 Days
• Field of Search: 257/59, 257/72, 349/42, 349/43
• US Class Current: 257/72
• CPC Class Codes: G02F 1/13458 Terminal pads
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line
• CPC Class Codes: G02F 1/136295 Materials; Compositions; Manufacture processes
• CPC Class Codes: H01L 27/1214 comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
• CPC Class Codes: H01L 27/124 with a particular composition, shape or layout of the wiring layers specially adapted to the circuit arrangement, e.g. scanning lines in LCD pixel circuits wiring structures per se H01L23/52
• CPC Class Codes: H01L 29/458 for thin film silicon, e.g. source or drain electrode
• CPC Class Codes: H01L 29/66757 Lateral single gate single channel transistors with non-inverted structure, i.e. the channel layer is formed before the gate

Abstract

A source line is directly connected to a source terminal composed of indium zinc oxide in a thin-film transistor substrate. A gate line is directly connected to a gate terminal composed of indium zinc oxide. Alternatively, drain electrodes of thin-film transistors for switching a plurality of pixel electrodes are directly connected to pixel electrodes composed of indium zinc oxide. These configurations do not require a passivation film which is essential for conventional thin-film transistor substrates, and the resulting thin-film transistor substrate can be made by a reduced number of manufacturing steps.

Claims

1. A thin-film transistor substrate comprising a gate line and a gate terminal, the gate terminal including one of indium tin zinc oxide and indium zinc oxide and being a different layer than the gate line, wherein the entirety of the gate line that overlaps the gate terminal is directly connected to the gate terminal, the indium tin zinc oxide is a compound oxide comprising indium oxide, tin oxide, and zinc oxide, the zinc content with respect to the total amount of zinc, indium, and tin is 1 atomic percent to 9 atomic percent, the atomic ratio of tin to zinc is at least 1, the tin content with respect to the total amount of zinc, indium, tin is 20 atomic percent or less, and the compound oxide exhibits at least partial crystallinity.

2. A thin-film transistor substrate according to claim 1, wherein the gate line comprises any one selected from the group consisting of aluminum, copper, molybdenum, chromium, titanium, tantalum, tungsten, and alloys thereof.

3. A thin-film transistor substrate according to claim 1, wherein the zinc content with respect to the total amount of zinc, indium, and tin is 2 atomic percent to 7 atomic percent, and the tin content with respect to the total amount of zinc, indium, and tin is 5 atomic percent to 10 atomic percent.

4. A liquid crystal display comprising a pair of substrates and a liquid crystal held between the pair of substrates, one of the pair of substrates being a thin-film transistor substrate according to claim 1.

5. A thin-film transistor substrate comprising drain electrodes constituting thin-film transistors to switch a plurality of pixel electrodes and pixel electrodes including one of indium tin zinc oxide and indium zinc oxide, each pixel electrode being a different layer than the corresponding drain electrode, wherein the entirety of each of the drain electrodes that overlap each of the pixel electrodes is directly connected to each of the pixel electrodes, the indium tin zinc oxide is a compound oxide comprising indium oxide, tin oxide, and zinc oxide, the zinc content with respect to the total amount of zinc, indium, and tin is 1 atomic percent to 9 atomic percent, the atomic ratio of tin to zinc is at least 1, the tin content with respect to the total amount of zinc, indium, tin is 20 atomic percent or less, and the compound oxide exhibits at least partial crystallinity.

6. A thin-film transistor substrate according to claim 5, wherein the drain electrodes comprise any one selected from the group consisting of aluminum, copper, molybdenum, chromium, titanium, tantalum, tungsten, and alloys thereof.

7. A thin-film transistor substrate according to claim 5, wherein the zinc content with respect to the total amount of zinc, indium, and tin is 2 atomic percent to 7 atomic percent, and the tin content with respect to the total amount of zinc, indium, and tin is 5 atomic percent to 10 atomic percent.

8. A liquid crystal display comprising a pair of substrates and a liquid crystal held between the pair of substrates, one of the pair of substrates being a thin-film transistor substrate according to claim 5.

9. A thin-film transistor substrate comprising a source line and a source terminal, the source terminal including one of indium tin zinc oxide and indium zinc oxide and being a different layer than the source line, wherein the entirety of the source line that overlaps the source terminal is directly connected to the source terminal, and the source line is connected with thin-film transistors, which are disposed in a region distinct from a region containing the source terminal,

wherein the indium tin zinc oxide is a compound oxide comprising indium oxide, tin oxide, and zinc oxide, the zinc content with respect to the total amount of zinc, indium, and tin is 1 atomic percent to 9 atomic percent, the atomic ratio of tin to zinc is at least 1, the tin content with respect to the total amount of zinc, indium, tin is 20 atomic percent or less, and the compound oxide exhibits at least partial crystallinity.

10. A thin-film transistor substrate comprising:

a substrate which is insulating at least at the surface thereof;

a plurality of gate lines and source lines in a matrix formed on the substrate;

pixel electrodes provided in regions surrounded by the gate lines and the source lines; and

thin-film transistors, each being connected to the corresponding pixel electrode, the corresponding gate line, and the corresponding source line and functioning as a switching element for the corresponding pixel electrode;

wherein each gate line is directly connected to a gate terminal comprising one of indium tin zinc oxide and indium zinc oxide, the gate lines and gate terminals are different lavers and the entirety of each gate line that overlaps the gate terminal is directly connected to the gate terminal, each source line is directly connected to a source terminal comprising one of indium tin zinc oxide and indium zinc oxide, the source lines and source terminals are different layers and the entirety of each source line that overlaps the source terminal is directly connected to the source terminal;

the pixel electrodes comprise one of indium tin zinc oxide and indium zinc oxide, and a drain electrode of each thin-film transistor is directly connected to the corresponding pixel electrode, the drain electrodes and pixel electrodes are different layers and entirety of each of the drain electrodes that overlap each of the pixel electrodes is directly connected to each of the pixel electrodes,

wherein the indium tin zinc oxide is a compound oxide comprising indium oxide, tin oxide, and zinc oxide, the zinc content with respect to the total amount of zinc, indium, and tin is 1 atomic percent to 9 atomic percent, the atomic ratio of tin to zinc is at least 1, the tin content with respect to the total amount of zinc, indium, and tin is 20 atomic percent or less, and the compound oxide exhibits at least partial crystallinity.

11. A thin-film transistor substrate comprising a source line and a source terminal, the source terminal including one of indium tin zinc oxide and indium zinc oxide and being a different layer than the source line, wherein the entirety of the source line that overlaps the source terminal is directly connected to the source terminal, and the source line is connected with thin-film transistors, which are disposed in a region distinct from a region containing the source terminal,

wherein the indium tin zinc oxide is a compound oxide comprising indium oxide, tin oxide, and zinc oxide, the zinc content with respect to the total amount of zinc, indium, and tin is 2 atomic percent to 7 atomic percent, the atomic ratio of tin to zinc is at least 1, the tin content with respect to the total amount of zinc, indium, and tin is 5 atomic percent to 10 atomic percent, and the compound oxide exhibits at least partial crystallinity.

12. A thin-film transistor substrate comprising:

a substrate which is insulating at least at the surface thereof;

a plurality of gate lines and source lines in a matrix formed on the substrate;

pixel electrodes provided in regions surrounded by the gate lines and the source lines; and

thin-film transistors, each being connected to the corresponding pixel electrode, the corresponding gate line, and the corresponding source line and functioning as a switching element for the corresponding pixel electrode;

wherein each gate line is directly connected to a gate terminal comprising one of indium tin zinc oxide and indium zinc oxide, the gate lines and gate terminals are different layers and the entirety of each gate line that overlaps the gate terminal is directly connected to the gate terminal, each source line is directly connected to a source terminal comprising one of indium tin zinc oxide and indium zinc oxide, the source lines and source terminals are different lavers and the entirety of each source line that overlaps the source terminal is directly connected to the source terminal;

the pixel electrodes comprise one of indium tin zinc oxide and indium zinc oxide, and a drain electrode of each thin-film transistor is directly connected to the corresponding pixel electrode, the drain electrodes and pixel electrodes are different layers and entirety of each of the drain electrodes that overlap each of the pixel electrodes is directly connected to each of the pixel electrodes,

wherein the indium tin zinc oxide is a compound oxide comprising indium oxide, tin oxide, and zinc oxide, the zinc content with respect to the total amount of zinc, indium, and tin is 2 atomic percent to 7 atomic percent, the atomic ratio of tin to zinc is at least 1, the tin content with respect to the total amount of zinc, indium, tin is 5 atomic percent to 10 atomic percent, and the compound oxide exhibits at least partial crystallinity.

13. A thin-film transistor substrate comprising a source line and a source terminal, the source terminal including one of indium tin zinc oxide and indium zinc oxide and being a different layer than the source line, wherein the entirety of the source line that overlaps the source terminal is directly connected to the source terminal, the indium tin zinc oxide is a compound oxide comprising indium oxide, tin oxide, and zinc oxide, the zinc content with respect to the total amount of zinc, indium, and tin is 1 atomic percent to 9 atomic percent, the atomic ratio of tin to zinc is at least 1, the tin content with respect to the total amount of zinc, indium, tin is 20 atomic percent or less, and the compound oxide exhibits at least partial crystallinity.

14. A thin-film transistor substrate according to claim 13, wherein the source line comprises any one selected from the group consisting of aluminum, copper, molybdenum, chromium, titanium, tantalum, tungsten, and alloys thereof.

15. A thin-film transistor substrate according to claim 13, wherein the zinc content with respect to the total amount of zinc, indium, and tin is 2 atomic percent to 7 atomic percent, and the tin content with respect to the total amount of zinc, indium, and tin is 5 atomic percent to 10 atomic percent.

16. A liquid crystal display comprising a pair of substrates and a liquid crystal held between the pair of substrates, one of the pair of substrates being a thin-film transistor substrate according to claim 13.