Ultra-thin gate-oxide characteristics and MOS/VLSI scaling implications

The properties of oxides (SiO2) in the 40- 300 Å region for MOS capacitors, MOSFET devices, and MOS/VLSI are experimentally determined in this investigation. Uniformity of oxide thickness, hard-wired short defects (pinholes), and latent defect densities are measured. The experimental data demonstrate that both MOS capacitors and transistors function classically with respect to Si/SiO2interface properties, threshold voltage, gm, etc. with oxide thickness well-below 100 Å. The MOSFET thin-oxide results are correlated with onset of short-channel effects. VLSI results are obtained with respect to 64K DRAM alpha immunity for storage-capacitor oxides of thickness 80- 455 Å. Extrapolations of device parameters indicate the necessity of reducing gate-oxide thickness to achieve super-scaled MOS/VLSI. When coupled to the experimental data base, these extrapolations indicate that utilization of oxide structures of thickness less than 100 Å may be of a more immediate nature than one might initially anticipate.