Search results
Results From The WOW.Com Content Network
These carrier concentrations will change if these materials are doped. For example, doping pure silicon with a small amount of phosphorus will increase the carrier density of electrons, n . Then, since n > p , the doped silicon will be a n-type extrinsic semiconductor .
Doping of a pure silicon array. Silicon based intrinsic semiconductor becomes extrinsic when impurities such as boron and antimony are introduced.. In semiconductor production, doping is the intentional introduction of impurities into an intrinsic (undoped) semiconductor for the purpose of modulating its electrical, optical and structural properties.
A degenerate semiconductor is a semiconductor with such a high level of doping that the material starts to act more like a metal than a semiconductor. Unlike non-degenerate semiconductors, these kinds of semiconductor do not obey the law of mass action, which relates intrinsic carrier concentration with temperature and bandgap.
While there is considerable scatter in the experimental data, for noncompensated material (no counter doping) for heavily doped substrates (i.e. and up), the mobility in silicon is often characterized by the empirical relationship: [37] = + + where N is the doping concentration (either N D or N A), and N ref and α are fitting parameters.
Silicon wafers are generally not 100% pure silicon, but are instead formed with an initial impurity doping concentration between 10 13 and 10 16 atoms per cm 3 of boron, phosphorus, arsenic, or antimony which is added to the melt and defines the wafer as either bulk n-type or p-type. [27]
The tool is used primarily for determining doping structures in silicon semiconductors. Deep and shallow profiles are shown in Figure 2. Figure 2 The shallow profile on the left, the deep profile on the right. Carrier concentration is plotted against depth. Regions with a net electron concentration are denoted as "n" (or n-type).
A dopant (also called a doping agent) is a small amount of a substance added to a material to alter its physical properties, such as electrical or optical properties. The amount of dopant is typically very low compared to the material being doped.
An extrinsic semiconductor is one that has been doped; during manufacture of the semiconductor crystal a trace element or chemical called a doping agent has been incorporated chemically into the crystal, for the purpose of giving it different electrical properties than the pure semiconductor crystal, which is called an intrinsic semiconductor.