Development of a 6-inch diameter VB-GaAs wafer

摘要

Development of a 6-inch Diameter VB-GaAs Wafer - by Shin-ichi Sawada, Tomohiro Kawase, Yoshiaki Hagi, Hideki Miyajima, Takashi Sakurada, Masashi Yamashita, Hiroaki Yoshida, Makoto Kiyama and Ryusuke Nakai - The market of cellular phones and othermobile communication systems has been expanding rapidly, and recently you have seen a marked trend toward lower power consumption, higher performance and lower price. GaAs-based devices have good high-frequency performances with low power consumption, and accordingly they are key components which are indispensable for mobile communication systems, although the request of cost reduction has become severe. The most effective approach to the cost reduction of device is to increase the diameter of GaAs wafer.Recently, using the VB growth technique, Sumitomo Electric has successfully developed 6-inch diameter GaAs crystals, whose diameter are significantly larger than conventional 3-4-inch diameter crystals. These 6-inch diameter VB wafers have an averagedislocation density of 3000-6000 cm{sup}(-2), which is one order of magnitude lower than conventional 6-inch LEC wafers. The residual strains VB wafers are less than half those of LEC and the VB wafers have higher resistance to slip generation duringdevice processing. We also confirmed that their electrical properties and flatness are as well as or better than those of conventional LEC wafers. We concluded that 6-inch diameter VB wafers are very promising wafers which can adequately meet userrequirements even in the future.