公开(公告)号：DE3684380D1

公开(公告)日：1992-04-23

申请号：DE3684380

申请日：1986-06-27

Applicant: IBM

Inventor： CSERVAK NANCY REBECCA ,  FRIBLEY SUSAN KAY ,  GOTH GEORGE RICHARD ,  TAKACS MARK ANTHONY

IPC: H01L21/76 ,  H01L21/302 ,  H01L21/3065 ,  H01L21/31 ,  H01L21/312 ,  H01L21/762

Abstract: A semiconductor structure (30) having dielectric isolation trenches is provided with an overlaying organic polyimide layer (48) filling the deep trenches. After over-filling the trenches with the polyimide, the polyimide layer (48) is non-planar and has a thickness much larger in the low trench density regions (44) than that in the high density regions (46). A photoresist layer is then applied thereover, and controllably exposed using a mask which is the complement or inverse of the mask used for imaging the trench patterns to obtain a thick blockout photoresist mask (54,56,58,60) over the trenches and a thin wetting layer (52) of photoresist over the remainder of the substrate. Next, by means of a thermal step, the blockout photoresist is caused to reflow to form a relatively thick photoresist layer over the high trench density regions and a thin photoresist layer over the low trench density regions, thereby exactly compensating for the non-planarity of the polyimide layer.