Physical Aspects of Negative Oxide Charge in p-MOS Capacitors with Annealed ITO Gates

Oleksandr Malik, F. Javier De la Hidalga-Wade

Properties of p-MOS capacitors with tin-doped indium oxide (ITO) gates have been investigated. The use of a transparent conducting gate is important for applications of p-MOS capacitors as optical sensors. A significant shift of the capacitance-voltage characteristics was observed, and this is explained as due to the presence of a negative oxide charge at the ITO-silicon dioxide interface. This negative charge comes from the presence of indium atoms that have diffused into the silicon dioxide.