Doping semiconductor is the controlled introduction of impurity atoms into a nearly pure crystal so engineers can set its electrical behavior. In silicon, this step is the foundation of transistors, diodes, and integrated circuits because it turns an intrinsic material with very low conductivity into a usable device-grade semiconductor.

The purpose of doping is simple: it creates mobile charge carriers. Donor atoms such as phosphorus, arsenic, or antimony add extra electrons and produce an n-type region. Acceptor atoms such as boron create holes and produce a p-type region. When these regions are combined, they form the junctions that make diodes, transistors, and many other semiconductor devices possible.

In real manufacturing, dopants are introduced by ion implantation or thermal diffusion, then activated by an anneal. Ion implantation gives precise depth and dose control, which is why it dominates advanced logic and memory production. Diffusion is still useful for simpler processes and for certain high-temperature steps where a broad, forgiving profile is acceptable.

<svg viewBox="0 0 760 470" xmlns="http://www.w3.org/2000/svg" font-family="-apple-system,Segoe UI,Roboto,sans-serif">
  <rect width="760" height="470" fill="#08131d"/>
  <rect x="26" y="24" width="708" height="422" rx="18" fill="#102032" stroke="#56748a" stroke-width="1.2"/>
  <text x="380" y="60" fill="#f5f7fb" font-size="20" font-weight="700" text-anchor="middle">Semiconductor Doping</text>
  <text x="380" y="84" fill="#89a7ba" font-size="12" text-anchor="middle">donors add electrons, acceptors create holes, and junctions form the basis of active devices</text>
  <rect x="120" y="140" width="220" height="160" rx="12" fill="#13253b" stroke="#4ec8ff"/>
  <text x="230" y="175" fill="#4ec8ff" font-size="14" font-weight="600" text-anchor="middle">N-type</text>
  <text x="230" y="215" fill="#c6e8ff" font-size="12" text-anchor="middle">Phosphorus / Arsenic</text>
  <text x="230" y="240" fill="#9ed7ff" font-size="12" text-anchor="middle">Extra electrons become carriers</text>
  <rect x="420" y="140" width="220" height="160" rx="12" fill="#13253b" stroke="#f59e0b"/>
  <text x="530" y="175" fill="#f59e0b" font-size="14" font-weight="600" text-anchor="middle">P-type</text>
  <text x="530" y="215" fill="#ffe1aa" font-size="12" text-anchor="middle">Boron / Gallium</text>
  <text x="530" y="240" fill="#ffd48a" font-size="12" text-anchor="middle">Missing electrons create holes</text>
  <path d="M340 220H420" stroke="#80c3ff" stroke-width="3" marker-end="url(#arrow)"/>
  <rect x="130" y="340" width="500" height="46" rx="10" fill="#0f1a26" stroke="#5e7887"/>
  <text x="380" y="368" fill="#91a8b8" font-size="11" text-anchor="middle">doping creates the carrier populations that enable transistors, junctions, and integrated circuits</text>
  <defs><marker id="arrow" viewBox="0 0 10 10" refX="8" refY="5" markerWidth="6" markerHeight="6" orient="auto"><path d="M0 0L10 5L0 10Z" fill="#80c3ff"/></marker></defs>
</svg>

In practice, semiconductor doping is one of the most important process steps in chip fabrication because it directly determines the carrier concentration, conductivity, and electrical performance of every active device.