Fabrication of submicron junctions-proximity rapid thermal diffusion of phosphorus, boron, and arsenic

Various techniques used in fabrication of deep submicron junctions are reviewed with respect to their advantages and disadvantages in silicon very large scale integration (VLSI) circuits technology. Proximity rapid thermal diffusion is then presented as an alternative process which results in very shallow junctions with high dopant concentrations at the surface. The feasibility of Si doping with B, P, and As for both planar and 3-D structures such as trench capacitors used in high density DRAM memories is shown based on sheet resistance measurements, secondary ion mass spectroscopy and scanning electron micrographs. Retardation effect of arsenic diffusion similar to the well known inhibition of silicon or SiO₂ deposition in chemical vapor deposition (CVD) processes is identified and discussed