silane and dichlorosilane are flowed into the process chamber along with a suitable carrier gas and or dopant s so as to form an epitaxial film on the substrate in some embodiments one or more etchant gases such as hcl cl 2 a combination of hcl and cl 2 etc may be flowed at the same time as the silicon source gasses e g during a simultaneous deposition etch process in other embodiments a separate etchant step may be employed following deposition e g during an ags process deposition and etching are continued until the desired epitaxial film thickness is achieved in some embodiments an sih 4 to dcs ratio of greater than 1 may be employed such as 2 1 3 1 4 1 5 1 7 1 10 1 etc sih 4 dcs other silicon source ratios may be used fig2 is a flowchart of a second exemplary method 200 for forming an epitaxial film in accordance with the present invention with reference to fig2 in step 201 a substrate is loaded into a process chamber and is heated to a temperature of about 800 u00b0 c or less in some embodiments a lower temperature range may be used during epitaxial film formation such as less than 750 u00b0 c less than 700 u00b0 c or less than 650 u00b0 c in step 202 silane and dichlorosilane are flowed into the process chamber along with a suitable carrier gas and or dopant s so as to form an epitaxial film on the substrate in some embodiments about 10 sccm to about 100 sccm of silane may be employed as may be about.