PROM programming method: Fusible-link PROMs are programmed by physically removing selected links with tools such as a microscope and tweezers. Is this characterization accurate?

Introduction / Context:
Programmable read-only memories (PROMs) historically used fusible links to store bits. Understanding the correct programming mechanism is important for historical and educational contexts and prevents misconceptions about how one-time programmability is achieved in silicon.

Given Data / Assumptions:

• Device type: fusible-link PROM (OTP PROM).
• Question claims physical removal of fuses with hand tools.
• We must decide whether this matches reality.

Concept / Approach:
Fusible-link PROMs are programmed electrically. A specialized programmer applies elevated current/voltage to selected links to blow (open) them internally. No manual mechanical operation takes place on the die. The statement describing a microscope and tweezers confuses semiconductor programming with physical rework, which is impractical and unnecessary for packaged ICs.

Step-by-Step Solution:

Verification / Alternative check:
Manufacturers specify programming algorithms and pulse parameters; no step mentions physical manipulation of links with tools. Photomicrographs show on-die links inaccessible post-packaging.

Why Other Options Are Wrong:

• Correct: Would imply manual surgery on the die, which is not the practice.
• Ambiguous / Mask ROM: Mask ROM is defined at fabrication, not by fuses blown post-fab.

Common Pitfalls:
Confusing laser-trimmed resistors or post-fab fuse techniques in analog IC trim with user PROM programming; both are internal and controlled, not manual tweezing.

Final Answer:
Incorrect