Semiconductor and Printed Circuit Board (PCB) Manufacturing
USHIO has become a titan of the semiconductor production market, defining industry standards while increasing market share and combining its long-standing experience with that of major semiconductor component manufacturers. We are a supplier of reliable, high-performance consumables and equipment for all process steps, starting with wafer manufacturing and lithography processes, right up to packaging, assembly, and inspection. Our focus is the production of zero-failure solutions with optimised cost efficiency in the fields of lithography, RTP (rapid thermal processing), cleaning, inspection, and measurement.
Depending on which process you wish to achieve, USHIO will be happy to call on its unmatched experience across the entire light spectrum to recommend the right ultraviolet (UV), vacuum-ultraviolet (VUV), or infrared (IR) emitter. Click the icons below to explore the semiconductor and printed circuit board (PCB) processes which USHIO is able to assist you with.
What is a Semiconductor?
A semiconductor is a crystalline material that possesses an intermediate electrical conductivity value between that of an insulator and a conductor. These materials have an electrical current resistance that is lower in one direction than the other.
Elemental semiconductors include silicon (Si) and germanium (Ge); however impurities can be intentionally added to create compound semiconductors, thereby altering the conductive properties. This process is known as semiconductor doping.
Silicon is the most common base material of doped or extrinsic semiconductors. Like germanium, silicon possesses 4 valence electrons in its outer orbital shell, which allows it to make strong covalent bonds. This property actually puts silicon more in line with typical insulators due to the low number of electrons available to facilitate conduction, but this can be adjusted through the addition of dopants.
N-Type and P-Type Silicon Semiconductors
Depending on whether the resulting doped material has a positive or negative charge, the new semiconductor material can be classified in one of two categories – N-type or P-type.
Toggle the semiconductor types below to learn about the differences between the two types of semiconductor.
Pentavalent elements with 5 valence electrons, such as phosphorus (P) and arsenic (As), are mixed with silicon in minute amounts. This means the spare 5th donor electrons is available to act as a charge carrier, which results in an enhanced electrical conductivity value. As electrons carry a negative charge (they flow from negative to positive), these doped semiconductor materials are called N-type semiconductors.
Trivalent elements with 3 valence electrons, such as gallium (Ga) and Aluminium (Al), are also mixed with silicon in minute amounts. This means there are holes where the missing 4th electron would create a bond. For materials to conduct electricity, these electron acceptor holes are vital because they allow free electrons to pass through the holes in the material and perform conductivity. P-type semiconductors are so called because they have more holes than electrons, so they carry a positive charge (they flow from positive to negative).
What is a P-N Junction?
The fundamentals of modern solid state electronics are built upon the P-N junction, which is formed when N-type and P-type semiconductors come into contact with each other. The connection between the two material types creates an environment where electricity can flow one way across the junction, but not the other.
As mentioned before, the N-type material has a majority of free electrons while the P-type material has a majority of holes. In the immediate vicinity of the P-N junction, those free electrons diffuse across the junction and into the holes, thereby creating a depletion region which acts as an insulating buffer zone.
The depletion region is so called because of the absence of free carriers in that area. This leaves a small electrical imbalance which, due to missing electrons, results in the N-type material gaining a positive charge. As a result, the electrons filling the holes within the P-type material have now imbued it with a negative charge.
When external voltage is applied to the P-N junction terminals, the flow of carriers can be altered to increase or decrease the width of the depletion region.
Charge carriers are attracted to the P-N junction. Subsequent decrease in depletion region width causes an increase in external potential. The diode completes the circuit and allows the maximum electrical current to flow through it, triggering the electron-hole diffusion process at the junction.
Charge carriers are drawn away from the P-N junction, which prevents the diffusion of electrons and holes. Increased depletion region width blocks most of the electrical current flow, preventing viable conduction.
No voltage applied, junction is in dynamic equilibrium.
The P-N junction is the basis of electrical functions for many semiconductor devices, and is a pivotal component in diodes, integrated circuits, LEDs, solar cells, and transistors. These devices themselves can then be implemented in a number of different ways. Diodes, for example, have a wide range of applications such as emitting light; radio wave and light detection; as a logic gate in computing; optical communication LASERs; voltage regulation, and the rectification of alternating current (AC) into direct current (DC).
Call on Ushio’s international expertise in the field of semiconductors
Ushio is ready to assist you in every way possible by placing decades of semiconductor and PCB industry experience at your disposal. Our lamp components play such a crucial role in the fabrication of microelectronics that we have acquired enough knowledge to produce our very own high-quality semiconductor-based emitters as well. This means Ushio is able to guide you to the right lighting solutions for every step of the manufacturing process, whether your interest lies in lithography, RTP (rapid thermal processing), cleaning, inspection, measurement, or if you are simply looking to purchase a top-quality, ready-made LED or laser diode component.
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