Low temperature Si epitaxy in a vertical LPCVD batch reactor

Silicon epitaxy on wafers is becoming more and more important for substrates in CMOS mass production, and has traditionally been used for bipolar and BiCMOS devices. This paper presents a new process solution in a vertical low-pressure chemical vapor deposition reactor allowing low cost batch processing for deposition of thin Silicon epitaxial layers at temperatures not exceeding 800°C. In situ cleaning of wafers in the reactor prior to the SiH4 deposition process shows significant influence on the quality of epitaxial layers. The problem of deposition on hot reactor walls has been solved by integration of remote plasma enhanced dry etching. We will present test results demonstrating the capabilities of the epitaxy process in this new tool. Finally, cost of ownership calculations will be presented showing the economic attraction of this new solution in comparison with single-wafer high temperature techniques.