I. Introduction
It is known that temperature sensors based on commercial silicon p-n junction diodes suffer from a number of substantial disadvantages showing themselves when measuring low temperatures. Due to comparatively low doping level of their bases (lower than critical value for the dielectric-metal transition, equal to cm−3 both in n-Si and in p-Si [1]), a freezing-out of the free current carriers takes place in them at low temperatures. An impact ionization of the frozen-out carriers by electric field causes an instability in the form of hysteresises in the diode current voltage characteristics (CVC) [2] that makes the measuring process impossible [2], [3]. Attempting to avoid such the instabilities, the manufacturers suggest to use high enough the sensor operation currents (10 or ) [4], that results in sensor self-hitting which distorts the sensor readings [5]. In particular, this shows itself as an irreproducibility of the measurement results under different sensor mountings [5], [6]. If even the operation current is chosen from the stability region, the diode conduction proves to be hopping and therefore strongly liable to magnetic-field influence. This fact makes the sensors of such type unusable at all for measuring low temperatures in the presence of magnetic field (see, for example, [7]). Similar statements are contained in all last review papers on this subject [8], [9].