High stress nitride film and method for formation thereof

• US 7,629,267 B2
• Filed: 03/06/2006
• Issued: 12/08/2009
• Est. Priority Date: 03/07/2005
• Status: Active Grant

• Current Assignee: ASM International NV
• Original Assignee: ASM International NV
• Inventors: Maes, Jan Willem, de Blank, Rene, Wan, Yuet Mei
• Primary Examiner(s): Rose; Kiesha L.
• Assistant Examiner(s): Anya; Igwe U
• Application Number:
  US11/370,228
• Publication Number:
  US 20060199357A1
• Time in Patent Office: 1,373 Days
• Field of Search: 257/52, 438/758
• US Class Current: 438/758
• CPC Class Codes: C23C 16/345 Silicon nitride
• CPC Class Codes: C23C 16/45523 Pulsed gas flow or change of composition over time
• CPC Class Codes: H01L 21/02115 the material being carbon, e.g. alpha-C, diamond or hydrogen doped carbon
• CPC Class Codes: H01L 21/0217 the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz H01L21/02126 and H01L21/0214 take precedence
• CPC Class Codes: H01L 21/02205 the layer being characterised by the precursor material for deposition
• CPC Class Codes: H01L 21/02321 introduction of substances into an already existing insulating layer H01L21/02227 and subgroups take precedence
• CPC Class Codes: H01L 21/3115 Doping the insulating layers
• CPC Class Codes: H01L 21/3185 of siliconnitrides
• CPC Class Codes: H01L 21/67017 Apparatus for fluid treatment H01L21/67126, H01L21/6715 take precedence
• CPC Class Codes: H01L 21/67115 mainly by radiation
• CPC Class Codes: H01L 29/7833 with lightly doped drain or source extension, e.g. LDD MOSFET's; DDD MOSFET's for thin film transistors H01L29/78618
• CPC Class Codes: H01L 29/7843 the means being an applied insulating layer

Abstract

A silicon nitride film is formed on a substrate in a reaction chamber by introducing trisilane and a reactive nitrogen species into the chamber in separate pulses. A carbon precursor gas is also flowed into the chamber during introduction of the trisilane and/or during introduction of the reactive nitrogen species, or in pulses separate from the trisilane and reactive nitrogen species pulses. The carbon is used as a dopant in the silicon nitride film and advantageously allows a high stress silicon nitride film to be formed.

Claims

1. A method of forming a silicon-containing compound layer, comprising:

loading a substrate into a reactor;

depositing a carbon-doped silicon layer on the substrate by exposing the substrate to a flow of a mixture containing trisilane and a dopant precursor, wherein the dopant precursor is an alkylsilane;

interrupting the flow of the mixture; and

forming an insulating silicon compound layer by exposing the silicon layer to a reactive nitrogen species while interrupting the flow of the mixture.

2. The method of claim 1, wherein the dopant precursor is chosen from the group consisting of mono-methyl silane, di-methyl silane, tri-methyl silane, tetra-methyl silane, mono-methyl disilane, di-methyl disilane, tri-methyl disilane, tetra-methyl disilane, mono-methyl trisilane, di-methyl trisilane, tri-methyl trisilane, and tetra-methyl trisilane.

3. The method of claim 2, further comprising selecting the dopant precursor based upon a desired silicon-containing compound layer dopant concentration, wherein relatively high carbon content species are selected for relatively high desired dopant concentrations and relatively low carbon content species are selected for relatively low desired dopant concentrations.

4. The method of claim 1, wherein depositing the silicon layer, interrupting the flow of the mixture and forming the silicon compound layer comprises repeatedly sequentially flowing the mixture and the reactive nitrogen species into the chamber.

5. The method of claim 1, wherein exposing the silicon layer to a reactive nitrogen species comprises exposing the silicon layer to nitrogen radicals.

6. The method of claim 5, wherein exposing the silicon layer to nitrogen radicals comprises remotely activating nitrogen gas, and wherein exposing the silicon layer to a reactive nitrogen species further comprises exposing the silicon layer to ammonia.

7. The method of claim 1, wherein exposing the silicon layer to a reactive nitrogen species comprises exposing the silicon layer to ammonia.

8. The method of claim 1, wherein the reactive nitrogen species is a remotely generated excited nitrogen species.

9. The method of claim 1, wherein the reactor is a furnace configured to accommodate a plurality of substrates.

10. The method of claim 9, wherein depositing a silicon layer is performed under reaction kinetics limited conditions.

11. The method of claim 9, wherein depositing a silicon layer, interrupting the flow of the mixture and forming the silicon compound layer comprises accommodating each of the plurality of substrates in the furnace vertically spaced from one another with major surfaces of the substrate extending horizontally.

12. The method of claim 1, wherein depositing the silicon layer, interrupting the flow of the mixture and forming the silicon compound layer comprises maintaining the substrate at a temperature between about 250°

C. and about 600°

C.

13. The method of claim 12, wherein the temperature is between about 300°

C. and about 500°

C.

14. The method of claim 1, wherein exposing the substrate to a flow of the mixture and comprises flowing trisilane to the reactor at a rate less than about 400.1 mg/minute.