Contact process using Y-contact etching

摘要

A method is disclosed for forming Y-shaped holes in semiconductor substrates by using Y-contact etching. The hole is formed with a single, two-step dry-etching process in a single chamber with one masking step for the whole hole. The upper portion of the Y-shaped hole is formed by means of an isotropic tapered dry-etching process while the lower portion is formed by means of a straight anisotropic recipe of the same dry-etching process. The result is a Y-shaped hole formed with fewer process steps and with maximized contact area for improved reliability.