Shallow donor formation in Si produced by proton bombardment

Abstract

Shallow donors have been created in Si by protons, H and H bombardment at room temperature followed by annealing above 300°C. The electron concentration profiles due to the shallow donors in the bombarded n-type region of the p+–n junction are determined by the Copeland method. The depth of the concentration peaks is 1 μm for every 100 kV for several hundred kV proton accelerating voltage, and a half and a third of the depth due to protons for H2+ and H3+ ions, respectively. These shallow donors disappear as the annealing temperature exceeds 700°C. For samples, bombarded at 300 °K but not annealed, only deep electron traps are observed. Most traps are annealed out above 300°C, by which the shallow donors emerge.