This paper investigates the fabrication of titanium silicided shallow p+/n junctions by BF3 implantation and diffusion. The implant dose and energy are fixed at 2 x 1015 cm-2, 20 keV. We investigate the effect of various furnace and rapid thermal annealing (RTA) cycles on the dopant profile and the junction depth by secondary ion mass spectroscopy (SIMS). We also report on reverse bias diode leakage of the —1800 A deep junctions with a background concentration of 1017 cm-3 P, below —500 Å thick TiSi2. Low leakage diodes are made by either furnace annealing at 850°C or RTA at 1050°C. However, the RTA is preferred over the furnace annealing because more B dose is active in the underlying Si. Shallower junctions are made by several techniques. Junctions made with Ge preamorphization are —200 Å shallower than those made without preamorphization. However, the diode leakage of the preamorphized diodes is significantly higher. Low temperature (500°C) recrystallization of the BF2-implanted Si before furnace diffusion results in junctions which are shallower by —300 A. Recrystallization has a negative effect on the junctions made by the preferred RTA process.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Surfaces, Coatings and Films
- Materials Chemistry