A NEW CVD REACTION FOR ATOMIC LAYER DEPOSITION OF SILICON

We have investigated a new reaction pathway for atomic layer depositio n of Si on various metal and semiconductor substrates using a novel or ganosilicon compound, Si(C6H10)(2), which has a central Si atom with t wo identical 5-fold hydrocarbon rings. Upon reaction with the substrat e the hydrocarbon rings are expected to transform into dimethylbutadie ne (C6H10)(2) which is very volatile and should readily desorb, thereb y leaving the Si core atoms adsorbed on the surface. High purity vapor sources of Si(C6H10)(2) were prepared and introduced into a multi-tec hnique ultrahigh vacuum (UHV) chamber. Si(C6H10)(2) molecule was initi ally physisorbed at Liquid nitrogen temperature(similar to 100 K) at a pressure of 1.0 x 10(-6) Torr to either monolayer or multi-layer thic kness on substrates. infrared reflection-absorption spectroscopy (IRAS ) and con-level X-ray photoelectron spectroscopy (XPS) of the Si(2p) h ave shown evidence of an adsorbed 'silylene' species formed at 200 K d ue to the loss of one 5-fold hydrocarbon ring. Thermal desorption data support the dissociation of the molecule and the liberation of the hy drocarbon reaction product, dimethylbutadiene. However, upon further h eating the 'silylene' species decomposes non-selectively to produce bo th silicon deposition and carbon contamination.