High sheet resistance, arsenic implanted polycrystalline silicon for integrated circuit resistors

The electrical properties of high sheet resistance polycrystalline silicon were investigated to facilitate its use in fabricating integrated circuit resistors. The effects of ion implantation dose, energy and annealing procedures were studied. Sheet resistances ranging from 10(2) to 10(9) omega/square were produced. A double depletion layer, thermionic emission model for electrical transport across grain boundaries accounts for many of the electrical properties, including the correlation of high activation energies with high sheet resistances. A reverse annealing peak in the sheet resistance is found for annealing temperatures between 800 and 1100 C. This irreversible effect is stronger in more lightly doped samples. The final sheet resistance value is primarily determined by the implantation dose and the highest processing temperature used.