p-type semiconductor

Silicon doped with acceptors, where holes are the majority carriers.

What you’ll learn

How acceptor doping works
Why holes carry current
Where p-type regions are used

Why it matters

The p-type counterpart to n-type completes the junction toolkit.

Explanation

Adding a group-III acceptor such as boron leaves an empty bonding site — a hole — that neighbouring electrons hop into, moving the hole through the lattice. Holes become the majority carriers, so current is carried mainly by positive charge.

As with n-type, the hole concentration follows the acceptor dose.

Visual explanation

A lattice dominated by holes (+), with a few free electrons as minority carriers.

Key terminology

Acceptor: A dopant that creates a hole.
Hole conduction: Current carried by the motion of holes.

Example

A p-type substrate hosts the NMOS transistors of a CMOS chip.

Common mistakes

Watch out for:

Imagining holes as physical particles — a hole is the collective motion of electrons.

Real-world application

PMOS source/drain regions are heavily p-type; the wafer bulk is often lightly p-type.

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