SPUTTERING TARGET AND THIN FILM TRANSISTOR EQUIPPED WITH SAME

• US 20120228608A1
• Filed: 11/18/2010
• Published: 09/13/2012
• Est. Priority Date: 11/19/2009
• Status: Active Grant

• Current Assignee: Idemitsu Kosan Company Limited
• Original Assignee: Idemitsu Kosan Company Limited
• Inventors: Yano, Koki, Itose, Masayuki
• Granted Patent: US 8,598,578 B2
• Time in Patent Office: Days
• US Class Current: 257/43
• CPC Class Codes: C01G 15/006 Compounds containing, besides gallium, indium, or thallium, two or more other elements, with the exception of oxygen or hydrogen
• CPC Class Codes: C01P 2002/72 by d-values or two theta-values, e.g. as X-ray diagram
• CPC Class Codes: C01P 2006/40 Electric properties
• CPC Class Codes: C04B 2235/3284 Zinc oxides, zincates, cadmium oxides, cadmiates, mercury oxides, mercurates or oxide forming salts thereof
• CPC Class Codes: C04B 2235/3286 Gallium oxides, gallates, indium oxides, indates, thallium oxides, thallates or oxide forming salts thereof, e.g. zinc gallate
• CPC Class Codes: C04B 2235/656 characterised by specific heating conditions during heat treatment
• CPC Class Codes: C04B 2235/6562 Heating rate
• CPC Class Codes: C04B 2235/6565 Cooling rate
• CPC Class Codes: C04B 2235/6567 Treatment time
• CPC Class Codes: C04B 2235/6585 at an oxygen percentage above that of air
• CPC Class Codes: C04B 2235/664 Reductive annealing
• CPC Class Codes: C04B 2235/768 Perovskite structure ABO3
• CPC Class Codes: C04B 2235/77 Density
• CPC Class Codes: C04B 2235/786 Micrometer sized grains, i.e. from 1 to 100 micron
• CPC Class Codes: C04B 2235/80 Phases present in the sintered or melt-cast ceramic products other than the main phase
• CPC Class Codes: C04B 2235/95 Products characterised by their size, e.g. microceramics
• CPC Class Codes: C04B 2235/96 Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
• CPC Class Codes: C04B 2235/963 Surface properties, e.g. surface roughness
• CPC Class Codes: C04B 35/01 based on oxide ceramics
• CPC Class Codes: C04B 35/453 based on zinc, tin, or bismuth oxides or solid solutions thereof with other oxides, e.g. zincates, stannates or bismuthates
• CPC Class Codes: C23C 14/08 : Oxides C23C14/10 takes precedence
• CPC Class Codes: C23C 14/3414 : Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy
• CPC Class Codes: H01L 21/02381 : Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02422 : Non-crystalline insulating materials, e.g. glass, polymers
• CPC Class Codes: H01L 21/02554 : Oxides
• CPC Class Codes: H01L 21/02565 : Oxide semiconducting materials not being Group 12/16 materials, e.g. ternary compounds
• CPC Class Codes: H01L 21/02631 : Physical deposition at reduced pressure, e.g. MBE, sputtering, evaporation
• 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

Abstract

A sintered body including an oxide that includes In, Ga and Zn at the following atomic ratio and includes a compound having as a main component a homologous crystal structure represented by InGaO₃(ZnO):

0.28≦Zn/(In+Zn+Ga)≦0.38

0.18≦Ga/(In+Zn+Ga)≦0.28.

Claims

1. A sintered body comprising an oxide that comprises In, Ga and Zn at the following atomic ratio and comprises as a main component a compound having as a main component a homologous crystal structure represented by InGaO₃(ZnO):

0.28≦

Zn/(In+Zn+Ga)≦

0.38

0.18≦

Ga/(In+Zn+Ga)≦

0.28.

2. The sintered body according to claim 1, wherein crystals of compounds represented by Ga₂O₃, ZnGa₂O₄, ZnO, In₂O₃, InGaO₃ and In₂O₃(ZnO)₃ are not observed in an analysis by X-ray diffraction.

3. The sintered body according to claim 1, wherein the atomic ratio of In, Ga and Zn of the oxide further satisfies the following formula:

0.59≦

In/(In+Ga).

4. The sintered body according to claim 1, wherein the oxide consists essentially of In, Ga, Zn and O.

5. A sputtering target comprising the sintered body according to claim 1.

6. The sputtering target according to claim 5 which has a relative density of 90% or more, a specific resistance of 15 m) cm or less, a surface roughness of 2 μ

m or less and an average crystal diameter of 10 μ

m or less.

7. A method for producing a thin film transistor comprising the step of forming a semiconductor layer using the sputtering target according to claim 5.

8. A thin film transistor prepared by using the sputtering target according to claim 5.