Effect of the doping level on temperature bistability in a silicon wafer

Temperature bistability in a silicon wafer with a doped layer on lamp-based heating

“…This relation is in good agreement with the results of numerical calculations for a uniformly doped silicon wafer [14]. Thus, for a heat system with the pure radiation heat transfer, the correction to the wafer temperature, i.e., the temperature difference between the wafer with doped layers or films and the substrate is unambiguously defines by the balance between the changes in the integrated emissivities of the wafer input and output surfaces (19).…”

“…On this basis, it can be concluded that, when presented to the heater, the doped layer, whose thickness is larger than the limiting thickness, weakens the bistability effect, and conversely, when presented to the absorber, the doped layer strengthens the effect. This feature follows from the fact that, for a uniformly doped wafer, the lower is the dopant concentration and the more efficient is heat removal from the wafer to the absorber, the more profound is the bistability effect [14]. In a wafer with a heavily doped layer, the former condition is satisfied, if the wafer surface with no layer is presented to the heater, and the latter condition is satisfied, if the wafer surface with a doped layer is presented to the absorber.…”

“…The dependence of the bistabililty effect on the impurity concentration in a doped silicon wafer was theoretically predicted and experimentally verified in [14]. A doped wafer can be simulated by a doped film, whose thickness is equal to the wafer thickness.…”

“…The possibility of the bistable behavior depends on the conditions of heat exchange between the silicon wafer and the elements of the working thermal reactor as well as on the optical and electrical properties of the wafer on its own. It is shown that the bistability appears under supplementary conductive or convective heat removal from the wafer and heavily depends on the doping level of the wafer [11,14]. According to Rudakov et al [11] and Ovcharov et al [14], the temperature bistability phenomenon in a silicon wafer in a water-cooled thermal reactor can be observed at low n-or p-type dopant concentrations up to $2 Â 10 17 cm À 3 [14].…”

“…It is shown that the bistability appears under supplementary conductive or convective heat removal from the wafer and heavily depends on the doping level of the wafer [11,14]. According to Rudakov et al [11] and Ovcharov et al [14], the temperature bistability phenomenon in a silicon wafer in a water-cooled thermal reactor can be observed at low n-or p-type dopant concentrations up to $2 Â 10 17 cm À 3 [14]. To observe the temperature bistability effect in a heavily doped silicon wafer, one needs specially designed reactors that operate at low temperatures of the cooling agent and, thus, provide conductive and convective heat removal from the wafer.…”