A novel two-dimensional MOS transistor for analog applications

In analog MOS integrated circuits, matching between transistors is a critical requirement because the circuit performance is determined by the device matching available. A new type of matched configuration is presented in this paper which utilizes the inherent 2-D geometry of an MOS transistor which was hitherto unexplored. This has been achieved by adding two more diffusion regions along the length of a normal MOS transistor. The characteristics of the device thus formed have been modeled in the linear region for different configurations, by solving the 2-D current continuity equation. For the saturation region, an empirical relation has been given. Theoretical and experimental results for a test chip have been presented. A few potential applications are mentioned.