A semiconductor is a material whose ability to conduct electricity falls between that of a conductor (which readily conducts electricity) and an insulator (which resists electricity). Commonly made from silicon, semiconductors can function as either depending on their environment. The semiconductor silicon serves as the base material for the microchip, also known as an integrated circuit or monolithic integrated circuit, a component used in almost every modern electronic device. Germanium also has a smaller band gap (0.66 eV) compared to silicon, which results in a higher intrinsic carrier concentration at room temperature. This property can be advantageous for certain applications, such as infrared (IR) detectors and thermoelectric devices, where a higher carrier concentration is desirable. One of the key advantages of germanium is its high electron mobility, which is approximately three times higher than that of silicon.
Doping is a process used to modify the electrical properties of semiconductor materials, such as silicon, by introducing impurities into their crystal lattice. These impurities, known as dopants, can either donate or accept electrons, creating n-type or p-type semiconductors, respectively. The ability to create n-type and p-type silicon is essential for the fabrication of electronic devices, as it allows for the formation of junctions that can control the flow of electrical current. Thin films can also be used to create insulators, such as silicon dioxide or aluminum oxide. These insulating films can be deposited on a substrate, such as a silicon wafer, to create a layer that prevents the flow of electric current. Thin films are used to create insulating layers in many electronic devices, including transistors and integrated circuits.
However, germanium still has some unique properties that make it an attractive choice for certain applications. In Semiconductors, we have a very small forbidden energy gap(around 1eV) and that’s why we have few free electrons present in the Conduction Band. At 0K temperature, the Conduction Band of the Semiconductor has no electrons, as all electrons are present in its valance shell. But on increasing the temperature, the electrons get sufficient energy to jump from the valance to the conduction band. So, at 0K, the semiconductor will behave as an insulator but at room temperature, it will behave as a semiconductor. The partial filling of the states at the bottom of the conduction band can be understood as adding electrons to that band.
List of semiconductor materials
This hole thus created takes the opposite charge of the electron and can be imagined as positive charge carriers moving in the lattice. The high electron mobility of germanium is one of its distinctive properties. The semiconductor can move electric currents more quickly thanks to this property than other metalloids like silicon or boron.
Conduction Band and Valence Band in Semiconductors
The wafers are then polished and cleaned to remove any impurities or defects that may have been introduced during the manufacturing process. The resulting wafers are then used as the basis for the production of computer chips and other electronic devices. Also, thin films are significant materials in the creation of semiconductor devices.
Silicon-based transistors and integrated circuits are fabricated through a series of processes, including photolithography, etching, and doping. Etching removes unwanted silicon material, leaving behind the desired structures, while doping introduces impurities into specific regions of the silicon to create n-type and p-type materials. Diodes are semiconductor devices that allow an electric current to flow in one direction while blocking it in the opposite direction. They consist of a junction formed by two layers of semiconductor material, one n-type and one p-type. When a positive voltage is applied to the n-type layer and a negative voltage to the p-type layer, the diode is said to be forward-biased, and current flows through the the most commonly used semiconductor is junction. Conversely, when the voltage polarity is reversed, the diode is reverse-biased, and the current flow is blocked.
- Testing is a critical step in the semiconductor manufacturing process, as it ensures that the final product meets the required performance specifications and is free of defects.
- They are used in fabrication photolithography, or “printing with light.” As the mask engineers finish each mask, they send them to fabrication factories — or fabs — to begin manufacturing.
- N-type silicon is created by doping silicon with donor impurities, which introduce extra electrons into the material, increasing its electrical conductivity.
- The electrons do not stay indefinitely (due to the natural thermal recombination) but they can move around for some time.
- The MOSFET (metal-oxide-semiconductor field-effect transistor) is the most common semiconductor device in the world.
Silicon in Integrated Circuits
Compound semiconductors are materials that are made up of two or more elements from different groups of the periodic table. These materials have unique electrical and optical properties that make them useful in a wide range of electronic and optoelectronic applications. Semiconductors are widely used in manufacturing electronics devices like transistors, diodes, sensors, integrated circuits.
Electron-hole pairs are constantly generated from thermal energy as well, in the absence of any external energy source. Semiconductors can conduct electricity under preferable conditions or circumstances. This unique property makes it an excellent material to conduct electricity in a controlled manner as required. At Wafer World, our team can provide you with high-quality materials to produce semiconductors.
Semiconductor manufacturing
At low temperatures, semiconductors allow little or no conductivity and act as insulators. At room temperature or when exposed to light, voltage, or heat, however, they can conduct electricity. It is this quasi state between conductors and insulators that makes semiconductors so important to electronic devices, as they control how, when, and where electricity flows.