Formation of advanced silicides using single wafer rapid thermal furnace in the temperature range of 200/spl deg/ - 1000/spl deg/C

Abstract

Various suicides are being used as ohmic contact materials for advanced silicon technologies. Due to the requirements for low contact resistance, no linewidth dependence and minimal thermal budget, different suicides are being adopted and modified to achieve the optimum characteristics. TiSi2 has been used to the 130 nm technology node with CoSi2 to the 100 nm node. Recently NiSi is being used to address 90 nm technologies and beyond. The formation of the various suicides was investigated using a single wafer rapid thermal furnace (SRTF) in the temperature range of 200degC to 1000degC. Utilizing an isothermal cavity process chamber, excellent temperature repeatability and uniformity can be achieved allowing investigation of the temperature sensitivity of the silicide formation. A 2-step process was used to minimize silicon consumption and control the diffusion of metal into the underlying materials, silicon, poly-Si and amorphous Si. The above mentioned suicides were investigated as used in manufacturing and the processing limits determined