Final answer:
The claim that rapidly cooling a heated wafer to regain its original resistivity is false. Heating and cooling alter the crystal structure and impurities, which changes the resistivity; it is not simply reversible by rapid cooling.
Step-by-step explanation:
The original question seems to pertain to the process of thermal treatment of semiconductors, and whether rapidly cooling a heated wafer will help regain its original resistivity. This statement is false. When semiconductors like a wafer are heated, the crystal structure can change and impurities can be introduced, which can alter the resistivity. Simply cooling it rapidly does not necessarily restore the original resistivity. In fact, as per Table 20.2 mentioned, the temperature coefficient of resistivity is negative for semiconductors listed, indicating that their resistivity decreases with increasing temperature, making them better conductors due to increased thermal agitation providing more free charges to carry current. When the material cools, these changes are not automatically reversed, and as a result, the resistivity may not return to its original state without further specific treatments.