Method for fabricating drive circuit and organic light-emitting diode display each having switching transistor without etch stopping layer on oxide semiconductor

• US 10,541,290 B2
• Filed: 03/29/2019
• Issued: 01/21/2020
• Est. Priority Date: 09/04/2014
• Status: Active Grant

• Current Assignee: Shanghai Tianma Micro-Electronics Company Limited (Tianma Microelectronics Company Limited), Tianma Microelectronics Company Limited
• Original Assignee: Shanghai Tianma Micro-Electronics Company Limited (Tianma Microelectronics Company Limited)
• Inventors: Zhai, Yingteng, Wu, Yong
• Primary Examiner(s): Jung, Michael
• Application Number:
  US16/370,500
• Publication Number:
  US 20190229167A1
• Time in Patent Office: 298 Days
• 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 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• CPC Class Codes: H01L 27/1251 comprising TFTs having a different architecture, e.g. top- and bottom gate TFTs
• CPC Class Codes: H01L 27/1288 employing particular masking sequences or specially adapted masks, e.g. half-tone mask
• CPC Class Codes: H01L 29/66765 Lateral single gate single channel transistors with inverted structure, i.e. the channel layer is formed after the gate
• CPC Class Codes: H01L 29/7781 with inverted single heterostructure, i.e. with active layer formed on top of wide bandgap layer, e.g. IHEMT
• CPC Class Codes: H01L 29/78669 with inverted-type structure, e.g. with bottom gate
• CPC Class Codes: H01L 29/78678 with inverted-type structure, e.g. with bottom gate
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/1213 the pixel elements being TFTs
• CPC Class Codes: H10K 59/124 Insulating layers formed between TFT elements and OLED elements

Abstract

A drive circuit, an organic light-emitting diode display, and methods for fabricating the same are provided. The drive circuit includes: a driving transistor, including a first gate, a first semiconductor layer disposed above the first gate, an etch stopping layer disposed on the first semiconductor layer, and a first source and a first drain which are disposed on the two sides of the first semiconductor layer, the first semiconductor layer being made of oxide semiconductor material; and a switching transistor, including a second gate, a second semiconductor layer disposed above the second gate, and a second source and a second drain which are disposed on two sides of the second semiconductor layer, the second semiconductor layer being made of oxide semiconductor material. In the drive circuit, reliability and uniformity of the drive transistors are improved, and parasitic capacitance of the switching transistor decreases.

Claims

1. A method for fabricating a drive circuit, comprising:

providing a substrate;

forming a first gate and a second gate on the substrate;

forming a gate dielectric layer to cover the first gate and the second gate;

forming a first semiconductor layer and a second semiconductor layer above the gate dielectric layer, wherein the first semiconductor layer corresponds to the first gate and is made of an oxide semiconductor material, and the second semiconductor layer corresponds to the second gate and is made of an oxide semiconductor material;

forming, above the first semiconductor layer, an etch stopping layer;

after the etch stopping layer is formed, forming a driving transistor by forming a first source and a first drain respectively on two sidewalls of the first semiconductor layer and two ends of the etch stopping layer;

forming a switching transistor by forming a second source and a second drain respectively on two sides of the second semiconductor layer, wherein the first source of the driving transistor is disposed directly from one end of the etch stopping layer to one of the two sidewalls of the first semiconductor layer, wherein the first drain of the driving transistor is disposed directly from another end of the etch stopping layer to another sidewall of the first semiconductor layer, wherein both the first source and the first drain are in direct contact with the gate dielectric layer; and

forming a dielectric layer to cover the driving transistor and the switching transistor.

2. The method for fabricating the drive circuit according to claim 1, wherein the forming an etch stopping layer at least comprises:

forming a lower layer above the first semiconductor layer using a metallic oxide; and

forming an upper layer above the lower layer using a nonmetallic compound.

3. The method for fabricating the drive circuit according claim 2, wherein the metallic oxide comprises at least one of alumina oxide, titanium oxide and yttrium oxide.

4. The method for fabricating the method according to claim 2, wherein the nonmetallic compound comprises at least one of silicon oxide, silicon nitride and silicon oxynitride.

5. The method for fabricating the drive circuit according to claim 2, wherein a thickness of the upper layer is in a range of 100 Å

-1000 Å

, and a thickness of the lower layer is in a range of 100 Å

-1000 Å

.

6. The method for fabricating the drive circuit according to claim 1, wherein a thickness of the etch stopping layer is in a range of 300 Å

-3000 Å

.