Dual glass reflow process for forming contacts.

摘要

A method for forming contact openings (19) in semiconductor devices. A borosilicate glass layer (13) is deposited over the gate and drain area (14, 11) of a device, followed by a borophosphosilicate glass layer (15). After masking with photoresist (16) and defining openings (17) the borophosphosilicate glass (15) is isotropically etched to undercut the resist layer (16). A plasma etch is utilized to anisotropically etch the borosilicate glass layer (13) and expose the surface of the drain area (11). After the photoresist (16) is stripped away, a reflow step is employed to reduce the sharp edges of the glass layer and result in a sloped contact opening profile. Good metal coverage is achieved while maintaining isolation of the gate (14).