Formation of a liquid-like silica layer by reaction of an organosilicon compound and a hydroxyl forming compound

• US 6,413,583 B1
• Filed: 06/22/1999
• Issued: 07/02/2002
• Est. Priority Date: 02/11/1998
• Status: Expired due to Term

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Moghadam, Farhad K., Xia, Li-Qun, Gaillard, Frederic, Venkataraman, Shankar, Lang, Chi-I, Yieh, Ellie, Jeng, Shin-Puu, Yau, Wai-Fan, Nemani, Srinivas, Cheung, David W.
• Primary Examiner(s): PADGETT, MARIANNE L
• Application Number:
  US09/338,470
• Time in Patent Office: 1,106 Days
• Field of Search: 427/563, 427/574, 427/579, 427/255.37, 427/249.15, 438/787, 438/788, 438/789, 438/790, 438/763
• US Class Current: 427/249.15
• CPC Class Codes: C23C 16/401 containing silicon
• CPC Class Codes: H01L 21/02126 the material containing Si, O, and at least one of H, N, C, F, or other non-metal elements, e.g. SiOC, SiOC:H or SiONC
• CPC Class Codes: H01L 21/02203 the layer being porous
• CPC Class Codes: H01L 21/02208 the precursor containing a compound comprising Si
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/02304 formation of intermediate layers, e.g. buffer layers, layers to improve adhesion, lattice match or diffusion barriers
• CPC Class Codes: H01L 21/02362 formation of intermediate layers, e.g. capping layers or diffusion barriers
• CPC Class Codes: H01L 21/31053 involving a dielectric removal step
• CPC Class Codes: H01L 21/3122 layers comprising polysiloxane compounds
• CPC Class Codes: H01L 21/31604 Deposition from a gas or vapour H01L21/31691, H01L21/31695 take precedence
• CPC Class Codes: H01L 21/31612 on a silicon body
• CPC Class Codes: H01L 21/76828 thermal treatment
• CPC Class Codes: H01L 21/76834 formation of thin insulating films on the sidewalls or on top of conductors H01L21/76831 takes precedence

Abstract

A method for depositing silicon oxide layers having a low dielectric constant by reaction of an organosilicon compound and a hydroxyl forming compound at a substrate temperature less than about 400° C. The low dielectric constant films contain residual carbon and are useful for gap fill layers, pre-metal dielectric layers, inter-metal dielectric layers, and shallow trench isolation dielectric layers in sub-micron devices. The hydroxyl compound can be prepared prior to deposition from water or an organic compound. The silicon oxide layers are preferably deposited at a substrate temperature less than about 40° C. onto a liner layer produced from the organosilicon compound to provide gap fill layers having a dielectric constant less than about 3.0.

Claims

1. A process for filling gaps between conductive materials on a semiconductor substrate, comprising:

reacting a silicon compound selected from a group consisting of methylsilane, dimethylsilane, trlmethylsilane, and combinations thereof, with a hydroxyl forming compound produced from an oxidizing gas comprising oxygen (O₂) and about 6-20 wt % of ozone (O₃) to deposit a film comprising silicon-carbon bonds on a patterned semiconductor substrate; and

curing the film to obtain a dielectric constant less than about 3.5.

2. The process of claim 1, wherein the silicon compound is trimethylsilane.

3. The process of claim 1, wherein the ozone reacts with water vapor to form the hydroxyl forming compound.

4. A process for depositing a low dielectric constant film, comprising:

depositing a first dielectric layer comprising silicon, oxygen, and carbon from process gases comprising trimethylsilane and a hydroxyl forming compound produced from an oxidizing gas comprising oxygen (O₂) and about 6-20 wt % of ozone (O₃);

depositing a second dielectric layer on the first dielectric layer; and

curing the first dielectric layer to obtain a dielectric constant less than about 3.5.

5. The process of claim 4, wherein the ozone is reacted wiht water vapor to form the hydroxyl forming compound.

6. The process of claim 4, wherein the first dielectric layer comprises silicon-carbon bonds and has from 1% to 50% carbon by atomic weight.