Diffused Resistor Temperature Coefficient Improvement

摘要

The purpose was to investigate the feasibility of using impurity compensation techniques to lower the temperature coefficient of resistance of silicon diffused resistors. The effect of impurity compensation on the temperature dependence of the resistivity has been investigated in heavily doped n and p-type silicon. Compensation effects were first investigated in bulk doped compensated silicon, and the range of impurity concentrations and compensation ratios that produce changes in the temperature dependence of the resistivity were established. These results were then applied to the formation of compensated diffused resistors having improved temperature coefficients of resistance. The temperature dependence of the resistance in silicon diffused resistors can be reduced to 2% over the range from -30C to +125C by compensation. However, a compensation ratio of approximately 50% is required and these effects occur only for carrier concentrations in the range from 8 x 10 to the 18th power to 2 x 10 to the 19th power/cu cm. Similar effects are found in both n and p-type silicon. In addition, it was found that using the optimum concentrations, the range of sheet resistance over which TCR improvement could be seen was 100 to 300 ohms per square. (Author)