Photoresist Deposition With Nitrogen To Suppress The Dewetting Problem
Original Publication Date: 1979-Oct-01
Included in the Prior Art Database: 2005-Feb-20
Larger and larger silicon wafers are processed in the semiconductor industry. With larger wafers, photoresist deposition becomes difficult because of the dewetting problem. Generally, the photoresist is deposited onto a substrate (for example, a semiconductor wafer coated by a silicon dioxide layer), disposed onto a rotating spintable (about 3500 RPM). TO cover the silicon dioxide layer with a thin photoresist film of 170000 Angstroms thick, an adhesion promoter is often applied on the oxide layer before the photoresist deposition in order to get a good photoresist adhesion during the subsequent oxide etching step. However, this surface pretreatment implies a shrinkage of the photoresist at the wafer edge with, consequently, a resist build up in the center portions. This effect is called "dewetting".