Abstract: In a method of forming a semiconductor device on a semiconductor substrate (100), a photoresist layer (102) is deposited on the semiconductor substrate; a window (106) is formed in the photoresist layer (102) by electron beam lithography; a conformal layer (108) is deposited on the photoresist layer (102) and in the window (106); and substantially all of the conformal layer (108) is selectively removed from the photoresist layer (102) and a bottom portion of the window to form dielectric sidewalls (110) in the window (106).

Abstract: Accordingly, this invention relates to an dry etching process for semiconductor wafers. More particularly, the present invention discloses a dry etching process including a halogen etchant (24) and a nitrogen gas (28) that selectively etches a compound semiconductor material (18) faster than the front-side metal layers (16A)(16B). Further, the dry etching process produces a vertical wall profile on compound semiconductor material (18) in both X (38) and Y (40) crystalline directions without undercutting the top of a via-opening.

Abstract: Accordingly, this invention relates to an dry etching process for semiconductor wafers. More particularly, the present invention discloses a dry etching process including a halogen etchant (24) and a nitrogen gas (28) that selectively etches a compound semiconductor material (18) faster than the front-side metal layers (16A)(16B). Further, the dry etching process produces a vertical wall profile on compound semiconductor material (18) in both X (38) and Y (40) crystalline directions without undercutting the top of a via-opening.

Abstract: An improved etching process for creating dimensionally accurate sub-micron and micron via-openings is disclosed. Specifically, this invention discloses a via etching process for a polymer layer (24) deposited on a semiconductor substrate (28) comprising the steps of: placing the semiconductor substrate comprising a polymer layer (24) deposited on the semiconductor substrate, a hard-mask (30) deposited on the polymer layer (24) and a photoresist mask (32) deposited on the hard-mask (30). The invention further, discloses performing a hard-mask opening step (34) comprising releasing a first fluoride gas (36) into the chamber. Furthermore, performing a polymer etching step (40) comprising releasing a second fluoride gas (42) into the chamber is disclosed. The invention also includes a hard-mask removal and tapered via step (46) to increase process margin.