The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 09, 2014
Filed:
May. 24, 2012
Gary Hillman, Livingston, NJ (US);
Gary Hillman, Livingston, NJ (US);
Other;
Abstract
An improved technique achieves a uniform photoresist film on a wafer by controlling the volatility of the solvent in a photoresist solution during the bake process step. Because film formation takes place in the bake rather than the spin steps of the process, the improved technique involves using less viscous and therefore less costly and easier to use resists to cast relatively thick photoresist films. Such control is achieved in an enclosed chamber into which a carrier gas is introduced; the carrier gas mixes with gaseous solvent to create a saturating atmosphere in which the rate of evaporation of solvent decreases. This enables the heating of the wafer without the reduction of solvent in the film so that the photoresist can self-level. When the film has self-leveled, the solvent is then baked off as usual.