Complete sputtering metallization for high-volume manufacturing

Abstract

In spite of the substantial progress made in the last decade, the GaAs IC industry is still far from reaching the high manufacturing yields established by the Si fabs. High volume applications that target the large consumer electronics market bring a new challenge to the ordinary GaAs manufacturing line and the lure to be more “Si-like” is the motivation for many new process developments. However, adopting Si methods often requires a hard re-thinking of the traditional paradigms established in the early years of GaAs IC processing. By implementing an all-sputtered metallization process in conjunction with CO 2 snow metal lift-off, we believe we overcame one such paradigm. We demonstrate that evaporation is not the only suitable method for lift-off patterning and show that sputtering could represent an attractive alternative. In this paper we will discuss some of the benefits and difficulties that come from using sputtering as the metal deposition method of choice in a high volume GaAs manufacturing line.