DOWNSTREAM AMMONIA PLASMA PASSIVATION OF GAAS

摘要

The inventors have discovered that by exposing gallium arsenide surfaces to downward ammonia plasma products, the surface can be passivated dry without heating or ion bombardment. Specifically, the gallium exposed by placing the workpiece into the exhaust chamber, then evacuating the chamber, generating an ammonia plasma at a distance from the workpiece, and lowering the plasma product into contact with the workpiece. The workpiece having the arsenide surface is surface passivated. It is preferable that plasma gas pressure is 0.5-0.6 Torr, the temperature of a board | substrate is less than 100 degreeC, and exposure time is 5 minutes or more. Plasma must be generated at a point far enough (about 10 cm or more away from the workpiece) to avoid collisions with the workpiece surface and ions, which may damage the workpiece surface, and the downwardly reactive plasma product must be generated. It should be generated close enough (within about 30 cm) to the workpiece so that it can reach, and the workpiece is placed outside the visible range of the plasma to prevent damage from radiation (UV, visible and X-ray). As a result, rapid and stable surface passivation at room temperature can be achieved which can be used in conjunction with the batch dry process techniques used to fabricate integrated circuits.