Method of forming vertically integrated current source

摘要

A current source MOSFET is fabricated by forming a trench (36) in an n++ drain (source) region (32) and extending below the trench (36). A gate oxide layer (40) is disposed on the sidewalls of the trench (36) and a conductive region (38) formed in the bottom of the trench (36). A gate-to-source (gate-to-drain) contact (49) is then formed in the trench (36) and then a drain (source) contact (58) formed. The vertical gate structure defines a vertical channel region on all sides of the trench (36) to allow a wider devive to be fabricated in a smaller overall silicon area.