Film forming method and film forming apparatus

Patent metadata

Field	Value
Publication number	US-10864548-B2
Application number	US-201815960885-A
Country	US
Kind code	B2
Filing date	Apr 24, 2018
Priority date	May 1, 2017
Publication date	Dec 15, 2020
Grant date	Dec 15, 2020

Abstract

A step of constantly supplying first and second carrier gases into a processing container having a substrate therein through first and second carrier gas flow paths, respectively, and supplying a source gas into the processing container through a source gas flow path, a step of purging the source gas by supplying a purge gas into the processing container through a purge gas flow path provided separately from the carrier gas, a step of supplying a reactant gas into the processing container through a reactant gas flow path, and a step of purging the reactant gas by supplying a purge gas into the processing container through the purge gas flow path are performed in a predetermined cycle. An additive gas having a predetermined function is supplied as at least a part of the purge gas in at least one of the purging steps.

First claim

What is claimed is:

1. A film forming method for forming a predetermined film, the film forming method comprising:
providing a film forming apparatus including:
a processing container configured to accommodate therein a substrate to be processed;
a gas supply configured to supply a source gas and a reactant gas for forming the predetermined film on the substrate to be processed, carrier gases for carrying the source gas and the reactant gas to the processing container and a purge gas for purging an interior of the processing container, respectively; and
a gas discharge configured to discharge gases in the processing container and maintain a vacuum atmosphere in the processing container,
wherein the gas supply includes a source gas flow path configured to supply the source gas into the processing container, a reactant gas flow path configured to supply the reactant gas into the processing container, a first carrier gas flow path and a second carrier gas flow path connected to the source gas flow path and the reactant gas flow path, respectively, and configured to supply the carrier gases for the source gas and the reactant gas, a purge gas flow path including a first purge gas flow path connected to the first carrier gas flow path and a second purge gas flow path connected to the second carrier gas flow path, and
wherein the purge gas flow path is configured to supply the purge gas for purging the interior of the processing container into the processing container by controlling a flow rate of the purge gas separately from the first carrier gas and the second carrier gas, an additive gas flow path configured to supply an additive gas having a predetermined function to the predetermined film, and opening/closing valves configured to independently open and close the source gas flow path, the reactant gas flow path, the first and second carrier gas flow paths, the purge gas flow path, and the additive gas flow path, respectively;

a first process of constantly supplying the carrier gases into the processing container through the first carrier gas flow path and the second carrier gas flow path in a state in which the substrate to be processed is disposed in the processing container;
a second process of causing the source gas to be adsorbed to a surface of the substrate to be processed by supplying the source gas into the processing container through the source gas flow path;
a third process of purging the source gas by stopping the supply of the source gas and supplying the purge gas into the processing container through the purge gas flow path;
a fourth process of causing the source gas and the reactant gas to react with each other by supplying the reactant gas into the processing container through the reactant gas flow path; and,
a fifth process of purging the reactant gas by stopping the supply of the reactant gas and supplying the purge gas into the processing container through the purge gas flow path,
wherein the purge gas is supplied into the processing container through the first and second purge gas flow paths at a flow rate which is higher than the flow rate of the first carrier gas and the second carrier gas, while not increasing the flow rate of the first and second carrier gases,
wherein the second to fifth processes are performed in a predetermined cycle, and
wherein the additive gas having the predetermined function is supplied through the additive gas flow path as at least a part of the purge gas in one or both of the third process of purging the source gas and the fifth process of purging the reactant gas.

2. The film forming method according to claim 1 , wherein the purge gas flow path has a gas storage configured to store the purge gas therein, and the purge gas is stored in the gas storage and then supplied into the processing container when pressure in the gas storage is increased and the valve provided in the purge gas flow path is opened.

3. The film forming method according to claim 1 , wherein the first purge gas flow path is further connected to the source gas flow path and the second purge gas flow path is further connected to the reactant gas flow path, and supplies the purge gas through the first purge gas flow path and the second purge gas flow path in the third process of purging the source gas and the fifth process of purging the reactant gas.

4. The film forming method according to claim 1 , wherein the source gas is TiCl 4 gas, the reactant gas is NH 3 gas, and the predetermined film is a TiN film.

5. The film forming method according to claim 4 , wherein the additive gas is H 2 gas.

6. The film forming method according to claim 5 , wherein a temperature during film forming is 400 to 750° C., H 2 gas is supplied as the additive gas in the fifth process of purging the reactant gas, and the H 2 gas serves to decrease specific resistance of the TiN film.

7. The film forming method according to claim 6 , wherein the second and fifth processes are repeated in multiple cycles, and time of the fifth process for a final cycle is prolonged and wherein the time is 60 seconds or less.

8. The film forming method according to claim 6 , wherein the second and fifth processes are repeated in multiple cycles, and the fifth process is periodically prolonged.

9. The film forming method according to claim 5 , wherein a temperature during film forming is 400 to 500° C., H 2 gas is supplied as the additive gas in both of the third process of purging the source gas and the fifth process of purging the reactant gas, and the H 2 gas serves to improve continuity of the TiN film.

10. The film forming method according to claim 5 , wherein H 2 gas is supplied as the additive gas only in the fifth process of purging the reactant gas or in both of the third process of purging the source gas and the fifth process of purging the reactant gas, and the H 2 gas serves to inhibit an etching action of TiCl 4 .

11. The film forming method according to claim 10 , wherein a temperature during film forming is within a range of 625 to 740° C.

12. The film forming method according to claim 10 , wherein a flow rate of the TiCl 4 gas is within a range of 50 to 270 sccm.

13. The film forming method according to claim 11 , wherein a flow rate of the TiCl 4 gas is within a range of 50 to 270 sccm.

Assignees

• Tokyo Electron Ltd

Inventors

• Ashizawa Hiroaki
• Fujii Yasushi
• Takahashi Tsuyoshi
• Hong Seokhyoung
• Yamazaki Kazuyoshi
• Nakamura Hideo
• Nunoshige Yu
• Kamio Takashi

Classifications

• H10P14/432

  using selective deposition · CPC title

• H10W20/033

  in openings in dielectrics · CPC title

• C23C16/45525

  Atomic layer deposition [ALD] · CPC title

• C23C16/34 Primary

  Nitrides {(C23C16/303 takes precedence)} · CPC title

• C23C16/45527

  characterized by the ALD cycle, e.g. different flows or temperatures during half-reactions, unusual pulsing sequence, use of precursor mixtures or auxiliary reactants or activations · CPC title