PE TEOS – Plasma Enhanced Tetraethyl Orthosilicate – Si(C2H5O)4
PE tetraethyl orthosilicate is a liquid film at room temperature and produces silicon dioxide layers for various applications. This film has great insulating properties and a wide range of uses. Plasma enhanced TEOS differs from other silicon dioxide films because it requires ozone (O3) during the reaction, lowering the deposition temperature. It also creates an oxide layer with very high conformity.
Depending on the application, some prefer this method to other SiOx film deposition techniques because it does not require the use of silane or dichlorsilane. Removing these gases improves the step coverage of the resulting film. It also allows for precise control of film stress, which is not possible in other silicon dioxide deposition methods.
PE TEOS is deposited in a system where wafers are first heated to between 200°C – 500°C. Once the furnace reaches the proper temperature, a gaseous TEOS mixture distributes uniformly through the system, parallel to the wafers. After distributing the gas evenly, radio-frequency energy between the gas and the surface of the wafers begins the deposition process. At the target temperature, TEOS begins to decompose, leaving a silicon dioxide layer anywhere between ~100Å and 30,000Å.
Low-particle tetraethyl orthosilicate goes through the same deposition process as PE TEOS. In order to maintain high purity, wafers are kept in a vacuum to prevent unwanted particles during the growth process. This process requires a hotter deposition chamber than PE TEOS because the tetraethyl orthosilicate does not begin to decompose until 700°C without the assistance of ozone.
To minimize particle contamination, SVM uses strictly virgin, factory sealed wafers for low particle TEOS.