Which method is used for fabrication of pn junction?

The diode (including the light-emitting diode) and the solar cell are silicon-based devices with similar fabrication processes and structure. Intentionally adding impurity “dopant” atoms to silicon in small concentrations can modify the electrical properties of the crystal, allowing the formation of a p-n junction.

What are the steps for fabrication of diodes?

Alloy and Diffused Diodes – Two commonly used techniques for Diode Fabrication Process and Packaging are the alloy method and the diffusion method. To construct an alloy diode, a pn-junction is formed by melting a tiny pellet of aluminum (or some other p-type impurity) on the surface of an n-type crystal.

How does a pn junction work?

When a p-n junction is formed, some of the free electrons in the n-region diffuse across the junction and combine with holes to form negative ions. In so doing they leave behind positive ions at the donor impurity sites. Show more detail of depletion region.

What is PN diode explain the common techniques used for the fabrication of pn diode?

In practice, the P-N junction is formed from a single mono crystalline structure by adding carefully controlled amounts of donor and acceptor impurities. The mono crystalline structure is formed through the use of a small seed of semiconductor (e.g., silicon or germanium). …

How are p-n junctions formed in semiconductors?

P-n junctions are formed by joining n -type and p -type semiconductor materials, as shown below. Since the n -type region has a high electron concentration and the p -type a high hole concentration, electrons diffuse from the n -type side to the p -type side. Similarly, holes flow by diffusion from the p -type side to the n -type side.

How is an electric field formed in a PN junction?

On the n -type side, positive ion cores are exposed. On the p -type side, negative ion cores are exposed. An electric field E forms between the positive ion cores in the n -type material and negative ion cores in the p -type material.

What do you need to make p-n junction diode?

Here discussion is limited only to acquaintation with the basic techniques and terminology (not expertise in fabrication). The first and foremost requirement is to obtain an extremely pure germanium or silicon.

What happens when filling a hole in the p-n junction?

Filling a hole makes a negative ion and leaves behind a positive ion on the n-side. A space charge builds up, creating a depletion region which inhibits any further electron transfer unless it is helped by putting a forward bias on the junction.