Abstract: A method of forming a floating gate memory array is provided that uses a two step etch process to prevent the formation of unwanted trenches 66 into the semiconductor substrate 26. The process may be accomplished by a first etch which is substantially not selective between silicon and dielectric materials. A second etch process is then used which is highly selective to dielectric materials.

Abstract: A process for forming a polysilicon line having linewidths below 0.35 .mu.m. The layer of polysilicon (20) is deposited over a semiconductor body (10). A layer of bottom anti-reflective coating (BARC) (30) is deposited over the polysilicon layer (20). A resist pattern (40) is formed over the BARC layer (30) using conventional lithography (e.g., I-line lithography). The resist pattern (40) has minimum dimensions of 0.30 .mu.m or greater. The BARC layer (30) is etched using the resist pattern (40) until the endpoint is detected. The BARC layer (30) and resist pattern (40) are then overetched using an isotropic etch having a selectivity of one-to-one between the BARC and resist. The overetch is a timed etch to control the linewidth reduction in the resist/BARC pattern. The minimum dimension of the pattern (50) is reduced to below 0.3 .mu.m. Finally, the polysilicon layer (20) is etched using the reduced width pattern (50).