Advances in CATT development - Performance at C-band

In a Controlled-Avalanche Transit-Time triode (CATT) device, avalanche multiplication in the collector depletion region of a silicon, bipolar, transistor-like structure is used to increase the gain, and thereby achieve higher frequency operation, of silicon bipolar transistors. It appears that with this additional gain silicon bipolars, designed and operated at CATT's, could become viable at C-band and higher frequencies without going to ultra-high resolution emitter-base patterns. The reported investigation was conducted to obtain a better understanding of the physics of CATT devices as a basis for the development of practical, three-terminal silicon power devices for higher frequency operation. The results of the investigation show that the CATT mechanism does provide higher gain and/or higher frequency operation than a comparable transistor structure. The CATT is found to be a more rugged device than a normal transistor. The emitter-base dynamics and lateral base effects are at least as important as the avalanche multiplication itself in determining CATT characteristics.