Low-temperature epitaxy using Si2H6

In the ULSI processes of the 1990s, the emphasis is expected to change from lateral to vertical down sizing in an attempt to achieve better device performance. Low-temperature CVD Si epitaxy will aid in this trend. It also offers the advantage of controllable selective deposition. We proposed three applications of low-pressure, low-temperature Si2H6 epitaxy with new designed reactors. One is half-micron epitaxy on buried layer. We successfully fabricated the bipolar transistor of half-micron epitaxy using the batch reactor of Si2H6 epitaxy. The other applications are formation of transistors having reduced parasitic capacitance and formation of shallow junction. These advanced applications require flexible conditions and low-temperature prebaking. We examined low temperature prebaking of 874° C using H2 and of 800° C using SiH2F2 with the singlewafer reactor. Also, low-temperature epitaxy of 632° C was observed with the singlewafer reactor.