Techniques for low temperature ion implantation are provided to improve throughput. Specifically, the pressure of the backside gas may temporarily, continually or continuously increase before the starting of the implant process, such that the wafer may be quickly cooled down from room temperature to be essentially equal to the prescribed implant temperature. Further, after the vacuum venting process, the wafer may wait an extra time in the load lock chamber before the wafer is moved out the ion implanter, in order to allow the wafer temperature to reach a higher temperature quickly for minimizing water condensation on the wafer surface. Furthermore, to accurately monitor the wafer temperature during a period of changing wafer temperature, a non-contact type temperature measuring device may be used to monitor wafer temperature in a real time manner with minimized condensation.