High performance poly-crystalline silicon thin film transistors fabricated using remote plasma chemical vapor deposition of SiO/sub 2/

摘要

A remote plasma chemical vapor deposition (RPCVD) of SiO/sub 2/ was investigated for forming an interface of SiO/sub 2//Si at a low temperature below 300/spl deg/C. A good SiO/sub 2//Si interface was formed on Si substrates through decomposition and reaction of SiH/sub 4/ gas with oxygen radical by confining plasma using mesh plates. The density of interface traps (D/sub it/) was as low as 3.4/spl times/10/sup 10/ cm/sup /spl minus/2/eV/sup /spl minus/1/. N- and p-channel Al-gate poly-Si TFTs were fabricated at 270/spl deg/C with SiO/sub 2/ films as a gate oxide formed by RPCVD and laser crystallized poly-crystalline films formed by a pulsed XeCl excimer laser. They showed good characteristics of a low threshold voltage of 1.5 V (n-channel) and /spl minus/1.5 V (p-channel), and a high carrier mobility of 400 cm/sup 2//Vs.