arrow 28 in fig1 one end of arm 26 a is rotatably coupled to base 24 while the other end of arm 26 a is rotatably coupled to one end of arm 26 b the other end of arm 26 b is rotatably coupled to one end of arm 26 c desirably arm 26 c is in the form of a paddle having one or more vacuum holes 30 disposed therein adjacent the distal end thereof vacuum holes 30 are coupled to a source of vacuum not shown which can deliver a vacuum to vacuum holes 30 under the control of controller 20 as shown in the figures semiconductor wafer 6 can be disposed on the distal end of arm 26 c and held thereon by means of a vacuum supplied to vacuum holes 30 desorption station 10 includes a circular heating plate 34 having a diameter that is desirably no less than the diameter of semiconductor wafer 6 one desirable construction of heating plate 34 includes one or more thick film resistors formed on a circular ceramic substrate circular heating plates of this type are available from watlow electric manufacturing company 6 industrial loop road p o box 975 hannibal mo 63401 usa however this particular form of heating plate is not to be construed as limiting the invention heating plate 34 is desirably spaced from a base of desorption station 10 by suitable standoffs 36 additionally standoffs 38 are arranged on a top surface of heating plate 34 for maintaining semiconductor wafer 6 in spaced parallel relation to heating plate 34 during desorption of one or more contaminants from semiconductor wafer 6 standoffs 36 and 38 are desirably formed from a high temperature glass.