Sige Epitaxy Improved by SI Cap Technology

With the chip manufacturing process continues to advance, traditional MOSFET devices are gradually reaching their physical limits. FDSOI technology was considered as an alternative to traditional devices. In the process research of FDSOI PMOS device, it was found that when the gate oxide (GOX) was grown directly on the SiGe channel, the CV curve of the device would hump significantly. According to theoretical analysis, it may be due to the interface state factors that exist because the gate oxide grows directly in the channel. Therefore, a process method of growing a layer of Si cap on SiGe channel and then growing GOX is proposed in this paper. After the growth of GOX, a thin layer of Si Cap is retained to improve the Dit and CV curves of SiGe. The experimental results show that hump of CV curve was improved after adjustment.