Field-effect transistors (FETs): If the drain, source, and channel are all p-type material and the device is specified to operate in both depletion and enhancement modes, is this device correctly identified as a p-channel enhancement-mode MOSFET (E-MOSFET)? Provide the best evaluation.

Introduction / Context:
MOSFET families include depletion-mode (D-MOSFET) and enhancement-mode (E-MOSFET) devices. Channel type (n-channel or p-channel) and operating mode (depletion, enhancement, or both) are fundamental identifiers. This question tests recognition of the distinction between p-channel E-MOSFETs and p-channel D-MOSFETs that can operate in both modes.

Given Data / Assumptions:

• Drain, source, and channel are p-type material (so the device is p-channel).
• The device is said to operate in both depletion and enhancement modes.
• We are classifying the device by standard MOSFET terminology.

Concept / Approach:
An enhancement-mode MOSFET (E-MOSFET) has no conducting channel at V_GS = 0; the channel is induced only when gate bias exceeds a threshold (for p-channel, V_GS is sufficiently negative). A depletion-mode MOSFET (D-MOSFET) has a physically present channel at V_GS = 0 and can conduct in depletion (V_GS near 0) and also be driven into enhancement (stronger magnitude of V_GS), effectively supporting both operating regions. Thus, “operates in both modes” points to a D-MOSFET, not an E-MOSFET.

Step-by-Step Solution:

Verification / Alternative check:
Look at transfer curves: D-MOSFET shows I_D at V_GS = 0 and modulates for negative V_GS (p-channel). E-MOSFET shows near-zero I_D until |V_GS| exceeds threshold; it cannot be “both-mode” by definition.

Why Other Options Are Wrong:
Correct: Contradicts the defining property of E-MOSFETs.

Ambiguous as stated / Cannot be determined: Mode wording is explicit; “both modes” uniquely indicates D-MOSFET behavior.

Common Pitfalls:
Confusing “p-channel” (conduction carrier type) with “enhancement” (bias mode). Assuming any p-channel device that can be turned off/on is automatically E-MOSFET.

Final Answer:
Incorrect