Linearization of the temperature dependence of the silicon´s resistivity for its use as a thermistor

An alternative method of processing silicon in order to linearize its resistivity-vs.-temperature characteristics is described. The method is based on the use of both shallow-level and deep-level acceptor impurities. Amphoteric impurities, such as gold and silicon, can be added to make minor adjustments of the sensitivities and the sample resistivity. This way of processing silicon can result in regions of 100 to 300°C wide, where the nonlinearity can be reduced to about ±0.1%, with a positive temperature coefficient of resistivity (TCR). This linearity is significantly better than those of commercially available semiconductor-based thermistors and is comparable to those of metal-based sensors. The thermal sensitivity of these devices can be set between 1000 and 2000 p.p.m./°C by controlling the impurities´ concentration. A linear regression analysis of the resistivity-vs.-temperature characteristics indicates that the R² factor may be as high as 0.999988. The corresponding device nonlinearities are maintained below ±0.25%, over a temperature range of 280°C