Method of fabricating transition metal dichalcogenide

Patent metadata

Field	Value
Publication number	US-9840764-B2
Application number	US-201514870014-A
Country	US
Kind code	B2
Filing date	Sep 30, 2015
Priority date	Sep 30, 2015
Publication date	Dec 12, 2017
Grant date	Dec 12, 2017

Abstract

A method of fabricating transition metal dichalcogenides includes a preparing step, a steaming step and a depositing step. The preparing step is performed for providing a transition metal substrate, a reactive gas and a solid chalcogenide. The steaming step is performed for heating the solid chalcogenide to generate a chalcogenide gas in a steaming space. The depositing step is performed for introducing the reactive gas into the chalcogenide gas to ionize the chalcogenide gas so as to generate a chalcogenide plasma in a depositing space. The depositing step is performed under a process vacuum pressure from low vacuum pressure to atmospheric pressure. The reactive gas and the chalcogenide gas are flowed from top to bottom through a top of the transition metal substrate. The loading substrate is heated at a loading substrate temperature, and the steaming space is different from the depositing space.

First claim

What is claimed is:

1. A method of fabricating transition metal dichalcogenides, comprising:
performing a preparing step for providing a loading substrate, a solid transition metal, a reactive gas and a solid chalcogenide, wherein the solid chalcogenide is a chemical element selected from the group consisting of sulfur, selenium, and tellurium;
performing a pre-plating step for heating the solid transition metal to generate a transition metal gas so as to deposit the transition metal gas on the loading substrate to form a transition metal oxide layer in a pre-plating space;
performing a steaming step for heating the solid chalcogenide to generate a chalcogenide gas in a steaming space;
performing a depositing step for introducing the reactive gas into the chalcogenide gas to ionize the chalcogenide gas so as to generate a chalcogenide plasma in a depositing space, wherein the chalcogenide plasma is reacted with a surface of the transition metal oxide layer to form a transition metal dichalcogenide layer by heating the loading substrate, and the depositing step is performed under a process vacuum pressure;
performing a thickness controlling step for changing the thickness of the transition metal oxide layer thereby changing the number of atomic layers corresponding to the transition metal dichalcogenide layer; and
performing a conversion controlling step for controlling a flow rate ratio of the reactive gas to change a conversion efficiency of the transition metal dichalcogenide layer during the process of the chalcogenide plasma reacting with the transition metal oxide layer;
wherein the steps of the method of fabricating transition metal dichalcogenides are carried out in order of the preparing step, the pre-plating step, the steaming step, the depositing step, the thickness controlling step, and where the step of the conversion controlling step is performed during the depositing step;
wherein in the depositing step, the reactive gas and the chalcogenide gas are flowed from top to bottom through a top of the transition metal oxide layer, the process vacuum pressure is performed from low vacuum pressure to atmospheric pressure, the loading substrate is heated at a loading substrate temperature from 150° C. to 500° C., and the depositing space is different from the steaming space and the pre-plating space;
wherein the process vacuum pressure is greater than or equal to 2 Torr and is smaller than or equal to 760 Torr;
wherein the depositing step is performed with a plasma power which is greater than or equal to 0 watt and smaller than or equal to 500 watts;
wherein after performing the pre-plating step, a thickness of the transition metal oxide layer is greater than or equal to 1 nm and smaller than or equal to 10 nm;
wherein the reactive gas comprises nitrogen and hydrogen.

2. The method of claim 1 , wherein the loading substrate is made of polyamide, stainless steel, glass, silicon nitride, silicon dioxide, aluminum oxide or hafnium oxide.

3. The method of claim 1 , wherein the solid transition metal is made of tungsten, molybdenum, nickel, copper, indium, germanium, tantalum, iron, cobalt or titanium.

4. The method of claim 1 , wherein the steaming step is for heating the solid chalcogenide at a steaming temperature from 90° C. to 150° C. when the solid chalcogenide is made from sulfur.

5. The method of claim 1 , wherein the steaming step is for heating the solid chalcogenide at a steaming temperature from 150° C. to 300° C. when the solid chalcogenide is made from selenium.

6. The method of claim 1 , wherein the steaming step is for heating the solid chalcogenide at a steam temperature from 400° C. to 650° C. when the solid chalcogenide is made from tellurium.

7. The method of claim 1 , wherein when the thickness is smaller than 7 nm and the loading substrate temperature is equal to 500° C., the plasma power is 0 watt.

8. The method of claim 1 , wherein the thickness controlling step is for generating one atomic layer corresponding to the transition metal dichalcogenide layer when the thickness is equal to 1 nm.

9. The method of claim 1 , wherein the flow rate ratio between nitrogen and hydrogen is 1:2 or 2:1.

10. The method of claim 1 , wherein the pre-plating step is for forming a transition metal oxide layer by an atomic layer epitaxy process, a sputtering process or an evaporation process.

11. The method of claim 1 , further comprising:
performing a transferring step for transferring the loading substrate out of the depositing space after the depositing step, wherein the loading substrate is made of flexible material; and
performing a mass production step for sequentially repeating the preparing step, the pre-plating step, the steaming step, the depositing step and the transferring step.

12. A method of fabricating transition metal dichalcogenides, comprising:
performing a preparing step for providing a loading substrate, a solid transition metal, a reactive gas and a solid chalcogenide, wherein the solid chalcogenide is a chemical element selected from the group consisting of sulfur, selenium, and tellurium;
performing a pre-plating step for heating the solid transition metal to generate a transition metal gas so as to deposit the transition metal gas on the loading substrate to form a transition metal layer in a pre-plating space;
performing a steaming step for heating the solid chalcogenide to generate a chalcogenide gas in a steaming space;
performing a depositing step for introducing the reactive gas into the chalcogenide gas to ionize the chalcogenide gas so as to generate a chalcogenide plasma in a depositing space, wherein the chalcogenide plasma is reacted with a surface of the transition metal layer to form a transition metal dichalcogenide layer by heating the loading substrate, and the depositing step is performed under a process vacuum pressure;
performing a thickness controlling step for changing the thickness of the transition metal layer thereby changing the number of atomic layers corresponding to the transition metal dichalcogenide layer; and
performing a conversion controlling step for controlling a flow rate ratio of the reactive gas to change a conversion efficiency of the transition metal dichalcogenide layer during the process of the chalcogenide plasma reacting with the transition metal layer;
wherein the steps of the method of fabricating transition metal dichalcogenides are carried out in order of the preparing step, the pre-plating step, the steaming step, the depositing step, the thickness controlling step, and where the step of the conversion controlling step is performed during the depositing step;
wherein in the depositing step, the reactive gas and the chalcogenide gas are flowed from top to bottom through a top of the transition metal layer, the process vacuum pressure is performed from low vacuum pressure to atmospheric pressure, the loading substrate is heated at a loading substrate temperature from 150° C. to 500° C., and the depositing space is different from the steaming space and the pre-plating space;
wherein the process vacuum pressure is greater than or equal to 2 Torr and is smaller than or equal to 760 Torr,
wherein the depositing step is performed with a plasma power which is greater than or equal to 0 watt and smaller than or equal to 500 watts;
wherein after performing the pre-plating step, a thickness of the transition metal layer is greater than or equal to 1 nm and smaller than or equal to 50 nm;
wherein the reactive gas comprises nitrogen and hydrogen.

13. The method of claim 12 , wherein the loading substrate is made of polyamide, stainless steel, glass, silicon nitride, silico

Assignees

• Univ Nat Tsing Hua

Inventors

• Chueh Yu-Lun
• Medina Henry
• Chen Yu-Ze
• Li Jian-Guang
• Su Teng-Yu

Classifications

• H10P95/00

  Generic processes or apparatus for manufacture or treatments not covered by the other groups of this subclass · CPC title

• C23C14/08 Primary

  Oxides (C23C14/10 takes precedence) · CPC title

• C23C16/00

  Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes (reactive sputtering or vacuum evaporation C23C14/00) · CPC title

• H01L35/00

  Electricity · mapped topic

• C23C14/5826

  Treatment with charged particles (C23C14/582 takes precedence) · CPC title