Which of these IC or semiconductor devices normally requires the most careful handling to avoid damage by static electricity?

The correct choice is CMOS. CMOS (Complementary Metal-Oxide-Semiconductor) technology is particularly sensitive to electrostatic discharge (ESD). This heightened sensitivity is due to the design and materials used in CMOS devices, which can lead to destruction or degradation when exposed to even small amounts of static electricity.

The gate oxide layers in CMOS devices are extremely thin, making them vulnerable to breakdown under high voltage levels typically associated with electrostatic discharge. This can result in permanent damage, which is not easily repairable. Consequently, when handling CMOS devices, it's essential to follow strict ESD precautions, using wrist straps, antistatic mats, and ensuring a controlled environment to mitigate the risk of discharge.

In contrast, while TTL (Transistor-Transistor Logic), bipolar devices, and discrete transistors also require careful handling, they generally have a higher tolerance to ESD compared to CMOS. This makes CMOS the most susceptible among the listed devices to damage from static electricity, reinforcing the need for heightened caution during handling and installation.