Stress management for tensile films

• US 7,935,643 B2
• Filed: 10/22/2009
• Issued: 05/03/2011
• Est. Priority Date: 08/06/2009
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Venkataraman, Shankar, Patel, Anjana M., Ingle, Nitin K., Liang, Jingmei
• Primary Examiner(s): Ghyka; Alexander G
• Assistant Examiner(s): MUSTAPHA, ABDULFATTAH B
• Application Number:
  US12/604,332
• Publication Number:
  US 20110034035A1
• Time in Patent Office: 558 Days
• Field of Search: 438761-790, 438/424, 257E21273-E21279, 257/E21.548
• US Class Current: 438/761
• CPC Class Codes: C23C 16/401 containing silicon
• CPC Class Codes: C23C 16/452 by activating reactive gas streams before their introduction into the reaction chamber, e.g. by ionisation or addition of reactive species
• CPC Class Codes: C23C 16/56 After-treatment
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• 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 21/02274 in the presence of a plasma [PECVD]
• 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 21/02326 into a nitride layer, e.g. changing SiN to SiON
• CPC Class Codes: H01L 21/02362 formation of intermediate layers, e.g. capping layers or diffusion barriers
• CPC Class Codes: H01L 21/31608 Deposition of SiO2 H01L21/31625, H01L21/31629 and H01L21/31633 take precedence
• CPC Class Codes: H01L 21/3185 of siliconnitrides
• CPC Class Codes: H01L 21/76829 characterised by the formation of thin functional dielectric layers, e.g. dielectric etch-stop, barrier, capping or liner layers
• CPC Class Codes: H01L 21/76834 formation of thin insulating films on the sidewalls or on top of conductors H01L21/76831 takes precedence
• CPC Class Codes: H01L 21/76837 Filling up the space between adjacent conductive structures; Gap-filling properties of dielectrics

Abstract

The formation of a gap-filling silicon oxide layer with reduced tendency towards cracking is described. The deposition involves the formation of a flowable silicon-containing layer which facilitates the filling of trenches. Subsequent processing at high substrate temperature causes less cracking in the dielectric film than flowable films formed in accordance with methods in the prior art. A compressive liner layer deposited prior to the formation of the gap-filling silicon oxide layer is described and reduces the tendency for the subsequently deposited film to crack. A compressive capping layer deposited after a flowable silicon-containing layer has also been determined to reduce cracking. Compressive liner layers and compressive capping layers can be used alone or in combination to reduce and often eliminate cracking. Compressive capping layers in disclosed embodiments have additionally been determined to enable an underlying layer of silicon nitride to be transformed into a silicon oxide layer.

Claims

1. A method of forming a silicon oxide layer on a substrate containing a trench, the method comprising:

transferring the substrate into a substrate processing region in a substrate processing chamber;

flowing a plasma precursor into a remote plasma region to form plasma effluents;

combining the plasma effluents with a flow of a silicon-containing precursor in the substrate processing region, wherein the flow of the silicon-containing precursor has not been excited by a plasma;

forming a silicon-and-nitrogen-containing layer on the substrate and in the trench;

forming a compressive capping layer over the silicon-and-nitrogen-containing layer; and

heating the substrate in an oxygen-containing atmosphere to convert the carbon-free silicon-and-nitrogen containing layer to the silicon oxide layer.

2. The method of claim 1 further comprising an operation of forming a compressive liner layer prior to the operation of forming the silicon-and-nitrogen-containing layer on the substrate.

3. The method of claim 1 further comprising an operation of curing the silicon-and-nitrogen-containing layer in an ozone-containing atmosphere prior to the operation of forming the compressive capping layer.

4. The method of claim 1 wherein the silicon-containing precursor comprises a silicon-and-nitrogen-containing precursor and the plasma effluents comprise a radical-nitrogen precursor.

5. The method of claim 4, wherein the silicon-and-nitrogen-containing precursor comprises at least one of H₂N(SiH₃), HN(SiH₃)₂, and N(SiH₃)₃ and the plasma precursor comprises at least one of N₂O, NO, NO₂, NH₄OH, NH₃, N₂ and H₂.

6. The method of claim 1, wherein the oxygen-containing atmosphere comprises at least one of O₂, O₃ and H₂O.

7. The method of claim 1, wherein the trench has a width of about 50 nm or less.

8. The method of claim 1, wherein the remote plasma region is within the substrate processing chamber and separated from the substrate processing chamber by a showerhead.

9. The method of claim 1, wherein the compressive capping layer is deposited using one of a furnace, PECVD, LP-CVD and HDP-CVD.