Electrical studies of metal-insulator-semiconductor structures
The capacitance-voltage(C-V) measurements at high frequency in metal-insulator-semiconductor ( MIS) structures provide important information about the interfacial parameters. The C-V characteristic measurements on MIS structures are reported in which silicon is used as the host semiconductor, and evaporated films of fatty acid as the insulator. The data are compared with devices containing Si02 on Si. It must be remarked here that II-VI and III-V group semiconductors lack the native oxide la- yer, and the purpose of this experimental studies is to assess the potential use of fatty acid film as insulator with these semiconductors. The d. c. dielectric breakdown properties and current-voltage measurements also have been investigated. This work shows that thermally evaporated stearic acid films can be potential substitutes as insulating layers in MIS devices. The magnitude of interface density of states are comparable in MIS structures containing only Si02 + fatty acid films. However, we have observed some unusual C-V characteristics on p-type silicon substrates, i.e., there is inversion under negative bias conditions which implies as if p-type surface is inverted to n-type. The fatty acid films also have lower dielectric strengths than Si02.