Load lock chamber and the cluster tool system using the same

Disclosed is a load lock chamber which includes a chamber body including: at least one pair of cavities, defined in a layer structure of the chamber body to carry one or more wafer substrates; at least one internal conduit, defined between and coupled with the paired cavities, such that the paired cavities are communicated with each other and capable of conducting gas refilling and exhaustion; and a plurality of wafer supports for carrying the wafer substrates, the plurality of wafer supports being securely received in the paired cavities and able to calibrate with a machine arm frontend finger, wherein the wafer support includes grooves defined thereon for calibrating the machine arm frontend finger.