Silicon based Semiconductor
requires low costs and high
Low level Trace Elements contamination control in Silicon wafers is one of the key factors to achieve these goals.
One technique used to monitor the level of contamination in Silicon wafers, from production to reclaim, is called Liquid Drop Decomposition ICP-MS (LDD ICP-MS) or Liquid Phase ICPMS (LP ICP-MS).
This technique relies upon the decomposition of a thin Silicon oxide layer (native or thermal) at the surface of the wafer by a mild etching solution, made of Hydrofl uoric Acid - Hydrogen peroxide (HF-H2O2).
A similar wafer surface contamination control technique uses a vapor phase etching step (Vapor Phase Decomposition ICP-MS or VPD ICP-MS) instead of liquid phase.
Considering its simplicity and repeatability, PRECILAB has elected to use the LP ICP-MS technique.
PRECILAB offers this technique for Silicon wafers up to 300 mm, (future development: 450 mm).
All solutions are made of low ppt grade materials. The wafers are handled under Class 1 conditions.
The use of one of the most sensitive quadrupole ICP-MS in the market (Varian MS-820) has permitted PRECILAB to reach very low Method Detection Limits.
Typical ICP-MS set-up:
Customer benefi ts with PRECILAB Silicon wafer surface:
LP droplet traveling over
a 200 mm Silicon wafer: