The present study reviews the use of Cl in gate oxidation furnaces for
growth of high quality gate oxides with a thickness in the range of 2 to 15
1nm. The following, commercially available, “state of the art” Cl-precursors
have been tested: 1,1,1- trichloroethane (TCA),
trans-1,2-dichloroethylene (DCE) and oxalyl chloride (OC).
Different parameters were evaluated including: metal removal efficiency,
poly-silicon haze, Fe bulk incorporation, carrier lifetime and
Cl-incorporation in the oxide. Cl2 was identified as the active
component in Cl-oxidation. As a consequence, OC was identified as being the
most efficient Cl-source. In particular, OC is the most suited Cl-source for
applications requiring reduced oxygen concentration, such as the
manufacturing of ultra thin gate oxides.