Surface chemistry relevant to material processing for semiconductor devices

Metal-oxide-semiconductor (MOS) structures are the core of many modern integrated circuit (IC) devices. Each material utilized in the different regions of the device has its own unique chemistry. Silicon is the base semiconductor material used in the majority of these devices. With IC device complexity increasing and device dimensions decreasing, understanding material interactions and processing becomes increasingly critical.; H{dollar}sb2{dollar} desorption is the rate-limiting step in silicon growth using silane under low temperature conditions. Activation energies for H{dollar}sb2{dollar} desorption measured during Si chemical vapor deposition (CVD) versus single-crystal studies are found to be significantly lower. It has been proposed that defect sites on the silicon surface could explain the observed differences. Isothermal H{dollar}sb2{dollar} desorption studies using laser induced thermal desorption (LITD) techniques have addressed this issue.; The growth of low temperature oxides is another relevant issue for fabrication of IC devices. Recent studies using 1,4-disilabutane (DSB) {dollar}rm(SiHsb3CHsb2CHsb2SiHsb3){dollar} at 100{dollar}spcirc{dollar}C in ambient O{dollar}sb2{dollar} displayed the successful low temperature growth of silicon dioxide (SiO{dollar}sb2).{dollar} However, these studies provided no information about the deposition mechanism. We performed LITD and Fourier transform infrared (FTIR) studies on single-crystal and porous silicon surfaces to examine the adsorption, decomposition, and desorption processes to determine the deposition mechanism.; Titanium nitride (TiN) diffusion barriers are necessary in modern metallization structures. Controlled deposition using titanium tetrachloride (TiCl{dollar}sb4){dollar} and ammonia (NH{dollar}sb3){dollar} has been demonstrated using atomic layered processing (ALP) techniques. We intended to study the sequential deposition method by monitoring the surface intermediates using LITD techniques. However, formation of a Cl impurity source, ammonium chloride {dollar}rm(NHsb4sp+Clsp-),{dollar} was observed, thereby, limiting our ability for effective studies.; Tetrakis(dimethylamino)titanium {dollar}rm(Tilbrack N{lcub}CHsb3{rcub}sb2rbracksb4){dollar} (TDMAT) is another precursor used in the CVD deposition of TiN films in IC devices. Thermal decomposition studies have demonstrated deviations from conformal deposition. Successful conformal deposition may be affected by readsorption of the reaction product, dimethylamine {dollar}rm(HNlbrack CHsb3rbracksb2).{dollar} Detailed studies were performed using LITD techniques in order to understand the adsorption and desorption kinetics of TDMAT and dimethylamine to gain insights about the conformal deposition of TiN.