A method for the joining of a ceramic shaft and a ceramic plate into an assembly, such as a heater, adapted to be used in semiconductor processing. The joined pieces are adapted to withstand the environments within a process chamber during substrate processing, chamber cleaning processes, and the oxygenated atmosphere which may be seen within the shaft of a heater or electrostatic chuck. The ceramic pieces may be aluminum nitride and the pieces may be brazed with aluminum. The joint material is adapted to withstand both the environments within a process chamber during substrate processing, and the oxygenated atmosphere which may be seen within the shaft of a heater or electrostatic chuck. The joint is adapted to provide a hermetic seal across the joint. The joined pieces are adapted to be separated at a later time should rework or replacement of one of the pieces be desired.