The stability of low-pressure chemical vapor-deposited TiB2 films has been investigated for their potenital use as diffusion barriers between A1 or Cu metallurgy and the Si substrate during post-metal annealing at temperatures ranging from 450-640~ for A1, and 500-800~ for Cu. Although no evidence of intermixing was observed via Rutherford backscattering spectroscopy (RBS) for TiB2/Si samples rapid thermal-annealing (RTA) up to 1080~ pyramid-shape pits in the Si, bounded by (111) planes, were observed using transmission electron microscopy for the samples annealed above 950~ Secondary ion mass spectroscopy depth profiles of B in Si originating from the TiB2 solid source suggested enhanced diffusion after RTA. According to RBS spectra coupled with scanning electron microscopy (SEM) examination, A1/TiB2/Si (pre-annealed) stacks appeared to be stable up to 500~ for 30 min in forming gas. For the stacks with as-deposited (amorphous) TiB2 films, plan-view SEM of A1/TiB2/Si showed very limited reaction with A1 up to 600~ in good agreement with sheet resistance measurements. The as-deposited, amorphous TiB2 films were superior diffusion barriers compared to the annealed, polycrystalline TiB2. No interaction took place between sputtered Cu and an underlying, amorphous TiB2 film up to 750~ 30 min in vacuum. Plan-view SEM, RBS, and sheet resistance measurements showed that the structure started to break down at 775~

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Thermal oxides ≃100 nm thick were exposed to 3:1 H2+N2 for 30 min at 950°C; similar films were treated in pure ammonia for 30 min at 950°C. The oxides were examined by high frequency and quasi‐static capacitance‐voltage measurements. A silicon internal reflection element (IRE) was processed in a similar manner in order to assess the effects of the thermal processing on the infrared spectrum of the thin film. The IRE was used for attenuated total reflection infrared spectroscopy, a technique that provides greater sensitivity to molecular groups such as Si‐OH, normalSi‐NHx , Si‐H, H2O , and NH3 (1, 2). Secondary ion mass spectrometry revealed the quantitative distributions of N, O, and H throughout a sample film. Ammonia exposure resulted in replacement of oxygen by nitrogen in the amorphous tetrahedral network. Films annealed in 75%H2:25%N2 (the expected dissociation products of NH3 ) were found to exhibit significantly different properties from films nitrided in NH3 , because NH3 did not attain thermodynamic equilibrium before coming in contact with the films. The H2+N2 anneal apparently increased the degree of oxygen bridging in SiO2 . Based on the IR data, a new model is proposed to explain the annealing of interface traps via H2 . Hydrogen is suspected to act as a catalyst, promoting bond rearrangement in the amorphous network. Nonbridging oxygen atoms are thought to bond to dangling silicon orbitals at the oxide/Si interface, thereby reducing the density of defects responsible for Dnormalit .