Multi-station sequential curing of dielectric films

• US 8,629,068 B1
• Filed: 05/03/2013
• Issued: 01/14/2014
• Est. Priority Date: 04/26/2005
• Status: Active Grant

• Current Assignee: Novellus Systems Incorporated (Lam Research Corporation)
• Original Assignee: Novellus Systems Incorporated (Lam Research Corporation)
• Inventors: Shrinivasan, Krishnan, Rivkin, Michael, Smargiassi, Eugene, Sabri, Mohamed
• Primary Examiner(s): Zervigon, Rudy
• Application Number:
  US13/886,694
• Time in Patent Office: 256 Days
• Field of Search: None
• US Class Current: 438/795
• CPC Class Codes: C23C 16/345 Silicon nitride
• CPC Class Codes: C23C 16/401 containing silicon
• CPC Class Codes: C23C 16/56 After-treatment
• 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 21/0217 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 21/02203 the layer being porous
• CPC Class Codes: H01L 21/02271 deposition by decomposition or reaction of gaseous or vapour phase compounds, i.e. chemical vapour deposition H01L21/02266 takes precedence
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/02282 liquid deposition, e.g. spin-coating, sol-gel techniques, spray coating
• CPC Class Codes: H01L 21/02348 treatment by exposure to UV light
• CPC Class Codes: H01L 21/3105 After-treatment
• CPC Class Codes: H01L 21/67115 mainly by radiation
• CPC Class Codes: H01L 21/68764 characterised by a movable susceptor, stage or support, others than those only rotating on their own vertical axis, e.g. susceptors on a rotating caroussel
• CPC Class Codes: H01L 21/68771 characterised by supporting more than one semiconductor substrate

Abstract

The present invention addresses provides improved methods of preparing a low-k dielectric material on a substrate. The methods involve multiple operation ultraviolet curing processes in which UV intensity, wafer substrate temperature and other conditions may be independently modulated in each operation. In certain embodiments, a film containing a structure former and a porogen is exposed to UV radiation in a first operation to facilitate removal of the porogen and create a porous dielectric film. In a second operation, the film is exposed to UV radiation to increase cross-linking within the porous film. In certain embodiments, the curing takes place in a multi-station UV chamber wherein UV intensity and substrate temperature may be independently controlled at each station.

Claims

1. A method of processing a semiconductor wafer, the method comprising:

performing a plurality of exposure operations providing wafer exposure characteristics differing in at least one of radiation intensity, radiation wavelength, and wafer support temperature, wherein each of the plurality of exposure operations is performed in a common processing chamber and at least two of the exposure operations have wafer exposure characteristics that vary in wavelength; and

transferring the semiconductor wafer between a first processing station and a second processing station within the common processing chamber, wherein;

the at least two of the exposure operations include a first exposure operation and a second exposure operation, and

the first exposure operation is performed on the semiconductor wafer at the first processing station and the second exposure operation is performed on the semiconductor wafer at the second processing station.

2. The method of claim 1, wherein the transferring is performed by rotating a carousel supporting the semiconductor wafer.

3. The method of claim 1, wherein the exposure operations are performed simultaneously on multiple semiconductor wafers at different processing stations within the common processing chamber.