METHOD OF MAKING COMPOUND SEMICONDUCTOR DEVICE

• Main Authors: SHIM, JAE YEOB, YOON, HYUNG SUP, KANG, DONG MIN, LEE, KYUNG HO, HONG, JU YEON
• Format: Patent
• Language: English
• Published: 11.06.2008
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

A method for fabricating a compound semiconductor device is provided to avoid a loss of the effective length of a gate electrode by performing a gate recess process in two steps. An etch stop layer(213) and an ohmic layer are formed on a schottky layer. A nitride layer(217) is formed on the ohmic layer. The nitride layer is patterned to form a fine gate pattern. The ohmic layer is selectively etched to form a first gate recess by using the fine gate pattern wherein the ohmic layer can form a recess profile of an undercut shape by a wet etch process. An oxide layer is deposited on the nitride layer to form an oxide layer spacer. The etch stop layer is etched to form a second gate recess. A gate metal is formed on the nitride layer. A first photoresist pattern is formed on the gate metal, and a first metal layer is formed on the first photoresist pattern. The first photoresist pattern is removed by a lift-off process to form a head portion of an asymmetrical gate electrode made wherein the head portion is made of the first metal layer. The gate metal is patterned by using the head portion of the asymmetrical gate electrode as a mask.