Semiconductor structure and methods for crystallizing metal oxide semiconductor layer

• US 10,446,691 B2
• Filed: 06/28/2017
• Issued: 10/15/2019
• Est. Priority Date: 06/29/2016
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: Ye, Jia-Hong
• Primary Examiner(s): Kim, Tong-Ho
• Application Number:
  US15/635,989
• Publication Number:
  US 20180006157A1
• Time in Patent Office: 839 Days
• Field of Search: 257 43
• CPC Class Codes: H01L 21/02178 the material containing aluminium, e.g. Al2O3
• CPC Class Codes: H01L 21/02244 of a metallic layer
• CPC Class Codes: H01L 21/02422 Non-crystalline insulating materials, e.g. glass, polymers
• CPC Class Codes: H01L 21/02425 Conductive materials, e.g. metallic silicides
• CPC Class Codes: H01L 21/02488 Insulating materials
• CPC Class Codes: H01L 21/02565 Oxide semiconducting materials not being Group 12/16 materials, e.g. ternary compounds
• CPC Class Codes: H01L 21/02592 amorphous
• CPC Class Codes: H01L 21/02667 Crystallisation or recrystallisation of non-monocrystalline semiconductor materials, e.g. regrowth
• CPC Class Codes: H01L 21/02672 using crystallisation enhancing elements
• 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 27/1255 integrated with passive devices, e.g. auxiliary capacitors
• CPC Class Codes: H01L 29/24 including, apart from doping materials or other impurities, only semiconductor materials not provided for in groups H01L29/16, H01L29/18, H01L29/20, H01L29/22 including organic materials H10K99/00
• CPC Class Codes: H01L 29/42356 Disposition, e.g. buried gate electrode H01L29/42324 and H01L29/4234 take precedence
• CPC Class Codes: H01L 29/66969 of devices having semiconductor bodies not comprising group 14 or group 13/15 materials comprising selenium or tellurium in uncombined form other than as impurities in semiconductor bodies of other materials, comprising cuprous oxide or cuprous iodide H01L21/02365
• 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: H01L 29/78696 characterised by the structure of the channel, e.g. multichannel, transverse or longitudinal shape, length or width, doping structure, or the overlap or alignment between the channel and the gate, the source or the drain, or the contacting structure of the channel H01L29/78612 takes precedence; transistors having a drain offset region or a lightly doped drain [LDD] H01L29/78621

Abstract

The present invention provides two methods for crystallizing a metal oxide semiconductor layer and a semiconductor structure. The first crystallization method is treating an amorphous metal oxide semiconductor layer including indium with oxygen at a pressure of about 550 mtorr to about 5000 mtorr and at a temperature of about 200° C. to about 750° C. The second crystallization method is, firstly, sequentially forming a first amorphous metal oxide semiconductor layer, an aluminum layer, and a second amorphous metal oxide semiconductor layer on a substrate, and, secondly, treating the first amorphous metal oxide semiconductor layer, the aluminum layer, and the second amorphous metal oxide semiconductor layer with an inert gas at a temperature of about 350° C. to about 650° C.

Claims

1. A method for crystallizing a metal oxide semiconductor layer, comprising:

forming an amorphous metal oxide semiconductor layer on a substrate, the amorphous metal oxide semiconductor layer comprising indium gallium zinc oxide, where a mole ratio of indium;

gallium;

zinc;

oxygen is 1;

1;

1;

4;

treating the amorphous metal oxide semiconductor layer with oxygen at a pressure of about 550 mtorr to about 5000 mtorr at a temperature of about 200°

C. to about 750°

C., and changing a part of the amorphous metal oxide semiconductor layer into an indium oxide crystallization layer; and

providing a radio-frequency power source, wherein when the amorphous metal oxide semiconductor layer is being treated with oxygen, the radio-frequency power source is provided with an output power;

wherein the indium oxide crystallization layer has a desirable acid-resistance characteristic, such that the indium oxide crystallization layer can resist an aluminum acid etchant obtained by mixing nitric acid, phosphoric acid, and acetic acid.

2. The method according to claim 1, further comprising:

heating the indium oxide crystallization layer.

3. The method according to claim 2, wherein the heating the indium oxide crystallization layer is performed at a temperature of about 200°

C. to about 800°

C.

4. The method according to claim 1, wherein when the amorphous metal oxide semiconductor layer is being treated with oxygen, the output power of the radio-frequency power source is greater than 0.