Device and methods for chemical vapor deposition

Patent metadata

Field	Value
Publication number	US-2023257882-A1
Application number	US-202217671965-A
Country	US
Kind code	A1
Filing date	Feb 15, 2022
Priority date	Feb 15, 2022
Publication date	Aug 17, 2023
Grant date	—

Abstract

Methods and systems for chemical vapor deposition (CVD) are disclosed. The methods and systems use a showerhead including a domed internal baffle plate. The domed internal baffle plate is perforated. The presence of the domed internal baffle plate improves the uniformity of gas distribution through the holes of the showerhead across the surface area of the showerhead. This improves deposition uniformity on the semiconducting wafer substrate upon which CVD is being performed, or improves the cleaning of the reaction chamber when a cleaning gas is pumped in through the showerhead.

First claim

What is claimed is:

1 . A chemical vapor deposition (CVD) method comprising:
introducing at least one process gas into a reaction chamber through a showerhead located above a substrate to be coated; wherein the showerhead comprises a gas inlet feeding into a plenum and a domed internal baffle plate at a mouth of the gas inlet, the domed internal baffle plate comprising a plurality of perforations.

2 . The method of claim 1 , wherein the perforations have an inlet diameter along an internal surface of the domed internal baffle plate and an outlet diameter along an external surface of the domed internal baffle plate; and wherein the inlet diameter is larger than the outlet diameter.

3 . The method of claim 2 , wherein a ratio of the inlet diameter to the outlet diameter is in a range of about 1.2 to about 2.6.

4 . The method of claim 1 , wherein the outlet diameter is from about 1.0 mm to about 2.1 mm.

5 . The method of claim 1 , wherein a ratio of a diameter of a domed portion of the domed internal baffle plate to a height of the domed internal baffle plate is from about 2.1 to about 10.8.

6 . The method of claim 1 , wherein a ratio of a diameter of a domed portion of the domed internal baffle plate to a diameter of the gas inlet is from about 1.32 to about 1.85.

7 . The method of claim 1 , wherein the at least one process gas comprises SiH 4 , N 2 , NF 3 , N 2 O, Ar, and O 2 for depositing a high-stress undoped silicate glass layer or an undoped silicate glass layer.

8 . The method of claim 1 , wherein a ratio of a total hole area of the domed internal baffle plate to a total hole area of the showerhead is from about 0.00164 to about 0.0170.

9 . The method of claim 1 , wherein a ratio of a total hole area of the domed internal baffle plate to a total surface area of the domed internal baffle plate is from about 0.06 to about 0.48.

10 . The method of claim 1 , wherein the at least one process gas includes one or more reactant gases and a carrier gas.

11 . The method of claim 1 , wherein the perforations comprise:
a first zone of perforations comprising a central hole and a first plurality of holes distributed circumferentially around the central hole; a second zone of perforations comprising a second plurality of holes distributed circumferentially around the first zone of perforations; and a third zone of perforations comprising a third plurality of holes distributed circumferentially around the second zone of perforations.

12 . The method of claim 11 , wherein:
the first plurality of holes is located at a diameter of about ⅙ to about ⅕ of a diameter of a domed portion of the domed internal baffle plate; or the second plurality of holes is located at a diameter of about ¼ to about ½ of a diameter of a domed portion of the domed internal baffle plate; or the third plurality of holes is located at a diameter of about ½ to about ¾ of a diameter of a domed portion of the domed internal baffle plate.

13 . The method of claim 1 , wherein a total hole area of the third zone is greater than a sum of a total hole area of the first zone and a total hole area of the second zone.

14 . A chemical vapor deposition device comprising:
a reaction chamber; a pedestal within the reaction chamber for supporting a wafer substrate; and a showerhead within the reaction chamber located above the pedestal; wherein the showerhead comprises a gas inlet feeding into a plenum and a domed internal baffle plate at a mouth of the gas inlet, the domed internal baffle plate comprising a plurality of perforations.

15 . The device of claim 14 , wherein the perforations have an inlet diameter along an internal surface of the domed internal baffle plate and an outlet diameter along an external surface of the domed internal baffle plate; and a ratio of the inlet diameter to the outlet diameter is from about 1.2 to about 2.6.

16 . The device of claim 14 , wherein a ratio of a diameter of a domed portion of the domed internal baffle plate to a height of the domed portion of the domed internal baffle plate is from about 2.1 to about 10.8; or
wherein a ratio of a diameter of a domed portion of the domed internal baffle plate to a diameter of the gas inlet is from about 1.32 to about 1.85.

17 . The device of claim 14 , wherein a ratio of a total hole area of the domed internal baffle plate to a total hole area of the showerhead is from about 0.00164 to about 0.0170; or
wherein a ratio of a total hole area of the domed internal baffle plate to a total surface area of the domed internal baffle plate is from about 0.06 to about 0.48.

18 . The device of claim 14 , wherein the showerhead further comprises a lower shower plate having from about 3000 to about 6000 holes; or wherein the device further comprises a radio frequency power supply for generating a plasma within the reaction chamber, or the device further comprises a purge gas evacuation device.

19 . A showerhead for a CVD system, comprising:
a lower shower plate with a plurality of holes; an outer sidewall about a circumference of the lower shower plate; an upper plate with a gas inlet at a center of the upper plate; and a domed internal baffle plate comprising a plurality of perforations; wherein the lower shower plate, the outer sidewall, and the upper plate together define a plenum, and the domed internal baffle plate is located within the plenum at the gas inlet.

20 . The showerhead of claim 19 , wherein a ratio of a total hole area of the domed internal baffle plate to a total hole area of the showerhead is from about 0.00164 to about 0.0170.

Assignees

• Taiwan Semiconductor Mfg Co Ltd

Inventors

• Liu Yung-Tsun
• Cheng Kuang-Wei
• Huang Sung-Ju
• Lee Chih-Tsung
• Ni Chyi-Tsong

Classifications

• C23C16/45565 Primary

  Shower nozzles · CPC title

• C23C16/401

  containing silicon · CPC title

• C23C16/45591

  Fixed means, e.g. wings, baffles · CPC title