High Sensitivity Temperature Sensors at Low Temperatures

High sensitivity temperature sensors (0.5<-1/R{\cdot}dR/dT<5) suitable for 1-10 K have been developed using n-type Si single crystals subjected to the thermal diffusion processes of phosphorus and to etching. They are very useful as low temperature thermometers and bolometers. Carbon film resistors developed as thermometers in a relatively weak magnetic field (up to 4 kOe) are described. They are also useful as temperature insensitive heaters in some cases.