At this point the basic steps of semiconductor production technology at the example of a field-effect transistor (FET) will be discussed. In addition, we describe the oldest and simplest method to implement a p-channel MOS-FET (metal-oxide semiconductor field-effect transistor). With this device can do Leitverhalten in an area between the so-called source and drain contacts on a further connection can be controlled, as the gate is designated. This is on an adjustable electric field, the number of free charge carriers in a single layer consequence of metal, insulator and semiconductor material influences (hence the name MOS-field effect transistors).

As a starting material is a n-doped silicon wafer.

Oxidation: In this step, the substrate on a nationwide silicon layer.



Structuring, lithography: The oxide film is now selectively removed so that a mask for specific ion implantation (doping).

This is the structure of chromium coating a glass mask on the oxide layer are transferred. This is done by following these steps:

Exposure: It will be an upset fotoempfindlicher paint, in places exposed, not hidden by the mask.



Develop: Here in the previous step of pre-exposure areas of the photoresist.



Etching: The residual lacquer, whose structure through the mask was given, in the following etching processes protects the underlying material layer, so that it only selectively removed.



Provisioning: The oxide film thus produced structured now serves as a mask for the doping process, which in selected areas of p-doped semiconductor material by introducing extraneous atoms arise. This is, for example by including accelerated by boron atoms.
The resulting endowed areas eventually serve as a source and drain contacts.



Oxidation: Now is the substrate in two further steps again with silica-coated, which are structured lithographic again. This results in first insulating separating walkways, the later the metal connectors of the individual contacts separate from each other. Thereafter, the so-called Feldoxid upset - the insulating layer, which ultimately control the leadership characteristics between source and drain contact.







Metallization: Finally, the contacts and traces of metal. This will be a full-aluminum coating, which then again with etching technology structured.