US-20260125794-A1 - METHOD FOR FORMING METAL OXIDE

US20260125794A1US 20260125794 A1US20260125794 A1US 20260125794A1US-20260125794-A1

Abstract

A novel method for forming a metal oxide is provided. The metal oxide is formed using a precursor with a high decomposition temperature while a substrate is heated to higher than or equal to 300° C. and lower than or equal to 500° C. In the formation, plasma treatment, microwave treatment, or heat treatment is preferably performed as impurity removal treatment in an atmosphere containing oxygen. The impurity removal treatment may be performed while irradiation with ultraviolet light is performed. The metal oxide is formed by alternate repetition of precursor introduction and oxidizer introduction. For example, the impurity removal treatment is preferably performed every time the precursor introduction is performed more than or equal to 5 times and less than or equal to 10 times.

Inventors

Shunpei Yamazaki
Tetsuya Kakehata
Sachiko Kawakami
Fumito Isaka
Yuji EGI

Assignees

SEMICONDUCTOR ENERGY LABORATORY CO., LTD.

Dates

Publication Date: 20260507
Application Date: 20260102
Priority Date: 20220715

Claims (15)

1 . A method for forming a metal oxide, comprising: a first step of supplying a first compound to a chamber and then supplying an oxidizer to the chamber; and a second step of supplying a second compound to the chamber and then supplying the oxidizer to the chamber, wherein the first compound comprises a first element selected from a group consisting of In, M, and Zn, wherein the second compound comprises a second element selected from the group consisting of In, M, and Zn, wherein the first element is different from the second element, wherein M represents one of Ga, Al, and Sn, wherein, in each of the first step and the second step, a substrate in the chamber is heated to higher than or equal to 300° C. and lower than or equal to 500° C., and wherein each of the first element and the second element is at least bonded to one of hydrogen, fluorine, chlorine, bromine, iodine, oxygen, phosphorus, sulfur, a hydroxy group, a thiol group, a boryl group, a substituted or unsubstituted phosphanyl group, a substituted or unsubstituted alkyl group comprising 1 to 8 carbon atoms, a substituted or unsubstituted alkenyl group comprising 2 to 8 carbon atoms, a substituted or unsubstituted alkynyl group comprising 2 to 8 carbon atoms, a substituted or unsubstituted cycloalkyl group comprising 3 to 10 carbon atoms, a substituted or unsubstituted cycloalkenyl group comprising 3 to 10 carbon atoms, a substituted or unsubstituted cycloalkynyl group comprising 3 to 10 carbon atoms, a substituted or unsubstituted alkoxy group comprising 1 to 6 carbon atoms, a substituted or unsubstituted alkylsulfanyl group comprising 1 to 6 carbon atoms, a substituted or unsubstituted 1,3-propanedialdehyde group, a substituted or unsubstituted aryl group comprising 6 to 30 carbon atoms, or a substituted or unsubstituted heteroaryl group comprising 2 to 30 carbon atoms in which a ring is formed by a plurality of elements selected from carbon, sulfur, oxygen, boron, and phosphorus.
2 . A method for forming a metal oxide, comprising: a first step of supplying a first compound to a chamber and then supplying an oxidizer to the chamber; and a second step of supplying a second compound to the chamber and then supplying the oxidizer to the chamber, wherein the first compound comprises a first element selected from a group consisting of In, M, and Zn, wherein the second compound comprises a second element selected from the group consisting of In, M, and Zn, wherein the first element is different from the second element, wherein M represents one of Ga, Al, and Sn, wherein, in each of the first step and the second step, a substrate in the chamber is heated to higher than or equal to 300° C. and lower than or equal to 500° C., wherein each of the first element and the second element is bonded to one or more of hydrogen, fluorine, chlorine, bromine, iodine, oxygen, phosphorus, sulfur, a hydroxy group, a thiol group, a boryl group, a substituted or unsubstituted phosphanyl group, a substituted or unsubstituted alkyl group comprising 1 to 8 carbon atoms, a substituted or unsubstituted alkenyl group comprising 2 to 8 carbon atoms, a substituted or unsubstituted alkynyl group comprising 2 to 8 carbon atoms, a substituted or unsubstituted cycloalkyl group comprising 3 to 10 carbon atoms, a substituted or unsubstituted cycloalkenyl group comprising 3 to 10 carbon atoms, a substituted or unsubstituted cycloalkynyl group comprising 3 to 10 carbon atoms, a substituted or unsubstituted alkoxy group comprising 1 to 6 carbon atoms, a substituted or unsubstituted alkylsulfanyl group comprising 1 to 6 carbon atoms, a substituted or unsubstituted 1,3-propanedialdehyde group, a substituted or unsubstituted aryl group comprising 6 to 30 carbon atoms, or a substituted or unsubstituted heteroaryl group comprising 2 to 30 carbon atoms in which a ring is formed by a plurality of elements selected from carbon, sulfur, oxygen, boron, and phosphorus, wherein a first oxide layer is formed using the first compound by an atomic layer deposition method, and wherein a second oxide layer is formed over the first oxide layer using the second compound by an atomic layer deposition method.
3 . A method for forming a metal oxide, comprising: a first step of supplying a first compound to a chamber and then supplying a first oxidizer to the chamber; and a second step of supplying a second compound to the chamber and then supplying a second oxidizer to the chamber, wherein the first compound comprises a first element selected from a group consisting of In, M, and Zn, wherein the second compound comprises a second element selected from the group consisting of In, M, and Zn, wherein the first element is different from the second element, wherein M represents one of Ga, Al, and Sn, wherein, in each of the first step and the second step, a substrate in the chamber is heated to higher than or equal to 300° C. and lower than or equal to 500° C., wherein each of the first element and the second element is at least bonded to one of hydrogen, fluorine, chlorine, bromine, iodine, oxygen, phosphorus, sulfur, a hydroxy group, a thiol group, a boryl group, a substituted or unsubstituted phosphanyl group, a substituted or unsubstituted alkyl group comprising 1 to 8 carbon atoms, a substituted or unsubstituted alkenyl group comprising 2 to 8 carbon atoms, a substituted or unsubstituted alkynyl group comprising 2 to 8 carbon atoms, a substituted or unsubstituted cycloalkyl group comprising 3 to 10 carbon atoms, a substituted or unsubstituted cycloalkenyl group comprising 3 to 10 carbon atoms, a substituted or unsubstituted cycloalkynyl group comprising 3 to 10 carbon atoms, a substituted or unsubstituted alkoxy group comprising 1 to 6 carbon atoms, a substituted or unsubstituted alkylsulfanyl group comprising 1 to 6 carbon atoms, a substituted or unsubstituted 1,3-propanedialdehyde group, a substituted or unsubstituted aryl group comprising 6 to 30 carbon atoms, or a substituted or unsubstituted heteroaryl group comprising 2 to 30 carbon atoms in which a ring is formed by a plurality of elements selected from carbon, sulfur, oxygen, boron, and phosphorus, wherein performing each of the first step and the second step one or more times and performing impurity removal treatment in an atmosphere containing oxygen is regarded as a first cycle, and wherein the first cycle is repeated a plurality of times.
4 . The method for forming a metal oxide, according to claim 1 , wherein the first compound and the second compound are each a liquid at 25° C. and 1 atm.
5 . The method for forming a metal oxide, according to claim 2 , wherein the first compound and the second compound are each a liquid at 25° C. and 1 atm.
6 . The method for forming a metal oxide, according to claim 2 , wherein the first compound and the second compound are each a liquid at 25° C. and 1 atm.
7 . The method for forming a metal oxide, according to claim 1 , further comprising a third step of supplying a third compound to the chamber and then supplying the oxidizer to the chamber, wherein the third compound comprises a third element selected from the group consisting of In, M, and Zn, wherein the third element is different from the first element and the second element, and wherein in the third step, the substrate is heated to higher than or equal to 300° C. and lower than or equal to 500° C.
8 . The method for forming a metal oxide, according to claim 2 , further comprising a third step of supplying a third compound to the chamber and then supplying the oxidizer to the chamber, wherein the third compound comprises a third element selected from the group consisting of In, M, and Zn, wherein the third element is different from the first element and the second element, and wherein in the third step, the substrate is heated to higher than or equal to 300° C. and lower than or equal to 500° C.
9 . The method for forming a metal oxide, according to claim 3 , further comprising a third step of supplying a third compound to the chamber and then supplying a third oxidizer to the chamber, wherein the third compound comprises a third element selected from the group consisting of In, M, and Zn, wherein the third element is different from the first element and the second element, and wherein in the third step, the substrate is heated to higher than or equal to 300° C. and lower than or equal to 500° C.
10 . The method for forming a metal oxide, according to claim 3 , wherein plasma treatment is performed as the impurity removal treatment.
11 . The method for forming a metal oxide, according to claim 3 , wherein the impurity removal treatment is performed while irradiation with ultraviolet light is performed.
12 . The method for forming a metal oxide, according to claim 3 , wherein microwave treatment is performed as the impurity removal treatment.
13 . The method for forming a metal oxide, according to claim 3 , wherein heat treatment at higher than or equal to 300° C. and lower than or equal to 500° C. is performed as the impurity removal treatment.
14 . The method for forming a metal oxide, according to claim 3 , wherein, in the first cycle, the first step or the second step that is less frequent or both of the first step and the second step are performed more than or equal to 5 times and less than or equal to 10 times.
15 . The method for forming a metal oxide, according to claim 3 , further comprising a third step of supplying a third compound to the chamber and then supplying a third oxidizer to the chamber, wherein the third compound comprises a third element selected from the group consisting of In, M, and Zn, wherein the third element is different from the first element and the second element, and wherein in the first cycle, the third step is performed one or more times before the impurity removal treatment.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention One embodiment of the present invention relates to a method for forming a metal oxide. One embodiment of the present invention relates to a semiconductor device including the metal oxide and a method for manufacturing the semiconductor device. One embodiment of the present invention relates to a transistor including the metal oxide and a method for manufacturing the transistor. Note that one embodiment of the present invention is not limited to the above technical field. Examples of the technical field of one embodiment of the present invention include a semiconductor device, a display device, a light-emitting device, a power storage device, a memory device, an electronic device, a lighting device, an input device (e.g., a touch sensor), an input/output device (e.g., a touch panel), a method for driving any of them, and a method for manufacturing any of them. In this specification and the like, a semiconductor device means a device that utilizes semiconductor characteristics, and refers to a circuit including a semiconductor element (e.g., a transistor, a diode, or a photodiode), a device including the circuit, and the like. The semiconductor device also means devices that can function by utilizing semiconductor characteristics. For example, an integrated circuit, a chip including an integrated circuit, and an electronic component including a chip in a package are examples of the semiconductor device. In some cases, a memory device, a display device, a light-emitting device, a lighting device, and an electronic device themselves are semiconductor devices and also include a semiconductor device. 2. Description of the Related Art A technique by which a transistor is formed using a semiconductor thin film formed over a substrate having an insulating surface has been attracting attention. The transistor is used in a wide range of electronic devices such as an integrated circuit (IC) or a display device. As semiconductor materials applicable to the transistor, silicon-based semiconductor materials have been widely used, but oxide semiconductors have been attracting attention as alternative materials. For oxide semiconductors, a c-axis-aligned crystalline (CAAC) structure and a nanocrystalline (nc) structure, which are neither a single crystal structure nor an amorphous structure, have been discovered (see Non-Patent Documents 1 and 2). Non-Patent Documents 1 and 2 disclose a technique for forming a transistor with the use of an oxide semiconductor having the CAAC structure. REFERENCES Non-Patent Documents [Non-Patent Document 1] S. Yamazaki et al., SID Symposium Digest of Technical Papers, 2012, Volume 43, Issue 1, pp. 183-186.[Non-Patent Document 2] S. Yamazaki et al., Japanese Journal of Applied Physics, 2014, Volume 53, Number 4S, pp. 04ED18-1-04ED18-10. SUMMARY OF THE INVENTION An object of one embodiment of the present invention is to provide a novel metal oxide and a formation method thereof. Another object of one embodiment of the present invention is to provide a miniaturized transistor. Another object of one embodiment of the present invention is to provide a transistor with a high on-state current. Another object of one embodiment of the present invention is to provide a transistor with favorable electrical characteristics. Another object of one embodiment of the present invention is to provide a highly reliable transistor or semiconductor device. Another object of one embodiment of the present invention is to provide a semiconductor device that can be miniaturized or highly integrated. Another object of one embodiment of the present invention is to provide a method for manufacturing the semiconductor device. Note that the description of these objects does not preclude the existence of other objects. One embodiment of the present invention does not need to achieve all of these objects. Other objects can be derived from the description of the specification, the drawings, and the claims. One embodiment of the present invention is a method for forming a metal oxide, including a first step of supplying a first compound to a chamber and then supplying an oxidizer to the chamber, and a second step of supplying a second compound to the chamber and then supplying the oxidizer to the chamber. The first compound is represented by any one of General Formulae (G1) to (G3). The second compound is represented by another one of General Formulae (G1) to (G3). In each of the first and second steps, a substrate in the chamber is heated to higher than or equal to 300° C. and lower than or equal to 500° C. In General Formulae (G1) to (G3), M represents Ga, Al, or Sn; each of R1 to R3 independently represents hydrogen (including deuterium), fluorine, chlorine, bromine, iodine, oxygen, phosphorus, sulfur, a hydroxy group, a thiol group, a boryl group, a substituted or unsubstituted phosphanyl group, a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, a