A variety of gases are used in semiconductor manufacturing for process reactions in chemical vapor deposition, etching, ion implantation and many other processes. They are also used for such diverse purposes as chamber cleaning and purging. Generally speaking, gases are classified as processes gases for the first set of applications and bulk gases for the second. Bulk gases are hydrogen, helium and nitrogen, for example, which can be produced on-site through air separation plants. Process gases are typically supplied in the familiar gas tanks, or sometimes gas tanker trailers if the volume required is high enough. In some parts of the world, underground piping is used to supply multiple fabs

Aside for the gas type, the most common concern is the purity of the gas. Purity is often discussed in the “number of nines” level of purity. Gases that are 99.999% pure, for example, are “five nines” purity, gases that are 99.9999% pure are “six nines” purity and so on. Alternatively, trance contaminants are measured in parts per million (ppm), parts per billion (ppb) or even parts per trillion (ppt). Higher levels of purity are, of course, more difficult to produce and are therefore more costly. They are also more difficult to measure accurately. An ongoing challenge in the semiconductor industry is that gas users — IC manufacturers — tend to specify the highest level of purity available, but it’s often unknown if that higher level of purity actually provides any kind of benefit to device performance or yield. Indeed, sometimes trace impurities have proved to have some kind of beneficial effect and removing them can actually decrease performance.

Another important aspect — some would say the most important aspect — is safety. Gases can be toxic, carcinogenic, flammable, pyrophoric, corrosive and generally hazardous. A silane leak, for example, could result in a pocket of silane in a corner of the fab, which could explode. Arsine and phosphine, commonly used in ion implantation, are deadly in ppb and ppt, respectively. Fortunately, the semiconductor industry has an excellent safety record and danger to fab personnel is minimal — as long as established safety protocols are closely followed. This include storing gas cylinders in well monitored gas cabinets.

SUPPLIERS


ARM Inc: www.arminc.com



Composites USA: http://www.compositesusa.com



CONSCI: http://www.consci.com



Critical Process System Group: http://www.cpsgrp.com



Fab-Tech, Inc.: http://www.fabtechinc.com



MoviTHERM: http://movitherm.com



SAES Pure Gas: http://www.saespuregas.com



ARTICLES



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SEMI and Solid State Technology announce 2017 “Best of West” Award finalists

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EV Group optimizes resist and lithographic processing for plasma dicing

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SEMICON West preview: Equipment components and subsystems

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Global semiconductor wafer-level equipment revenue to grow 11% in 2016

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3D-Micromac receives large volume orders from solar industry for its microCELL TLS system

04/18/2017  3D-Micromac AG today announced that the total received order volume for its microCELL TLS high-throughput half-cell cutting tools tops 1.5 GW for tool deliveries in 2017 to date.

EVG breaks speed and accuracy barrier in mask alignment lithography for semiconductor packaging

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Record spending for fab equipment expected in 2017 and 2018

03/07/2017  Today, SEMI announced updates to its World Fab Forecast report, revealing that fab equipment spending is expected to reach an industry all-time record − more than US$46 billion in 2017.

Global MEMS manufacturer selects ULVAC Technologies' plasma ashing system

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ClassOne initiative aims to reduce CoO in ≤200mm copper plating

02/22/2017  ClassOne Technology announced a new company-wide initiative to reduce costs of operation (CoO) in copper plating processes.

SEMI appoints Ajit Manocha as president and CEO

02/21/2017  SEMI today announced the appointment of Ajit Manocha as its president and CEO.

Executive viewpoints: 2017 outlook

01/25/2017  Each year, Solid State Technology turns to industry leaders to hear viewpoints on the technological and economic outlook for the upcoming year. Read through these expert opinions on what to expect in 2017.