A review of bulk semiconductor microwave control components

The use of semiconductor bulk phenomena in implementing microwave control components is reviewed. The principal phenomena explored to date have been the dielectric and conductive properties of the plasma state. A brief discussion of these properties is presented to identify their potentially useful characteristics for microwave control. It is noted that to date only the conductive plasma properties have proved practical for application. More specifically, electron-hole plasmas, generated by impact ionization or by contact injection, existing in silicon have been successfully incorporated in microwave circuitry to yield control components with substantially improved performance over junction devices. Examples of the design, fabrication, and results obtained for bulk semiconductor control components are presented illustrating the application of impact ionization to limiter and duplexer operation and contact injection utilizing a window configuration to switching and phase shifting operation. The principal improvements are gained through achieving at least an order of magnitude increase in power handling and full guide bandwidth in utilizing the window. In addition, it is noted that the bulk approach is virtually the only practical semiconductor approach for millimeter wave control components.