Final answer:
The speed of a MOSFET at increased temperatures depends on the material's temperature coefficient of resistivity. For semiconductors with a negative coefficient, speed could increase due to better conductivity; for those with a positive coefficient, the speed may decrease.
Step-by-step explanation:
The main answer to the question of whether a MOSFET operates faster as temperature increases is, it depends on the material used in the MOSFET. In general, for semiconductors, as temperature increases, the resistivity usually decreases because thermal agitation increases the number of free charges available to carry current. This could potentially make the MOSFET more responsive or 'faster' at higher temperatures. However, there are trade-offs as the increased lattice vibrations at higher temperatures can also scatter charge carriers, potentially leading to lower mobility and slower device operation.In most conducting metals used in electronics, resistivity increases with increasing temperature. Increased temperature causes an increase in atom vibrations within the material's lattice structure which can impede the motion of electrons. Therefore, in such materials, a rise in temperature can actually cause a MOSFET to become slower.The temperature coefficient of resistivity, which can be positive or negative depending on the material, is crucial in determining the effect of temperature on a MOSFET's speed. Negative temperature coefficient semiconductors could potentially become faster with increased temperature, within certain limits, as they become better conductors. However, for materials with positive temperature coefficients, the opposite is true.