NON-SILVER PASTE METHOD FOR MAKING THERMAL CONTACT TO SUBSTRATES FOR HIGH T-c FILM GROWTH

We describe a procedure for using thin layers of gold foil for making thermal contact between insulating substrates and Haynes alloy heater blocks. This method has several advantages over silver paste compounds routinely used to improve the thermal contact. Samples are easily removed from the metal blocks after heating up to 850 C, and no pre-bake process is required prior to sample loading into the deposition chamber since no organic binder is used. Because only a thin layer (1 mu m thick) of gold foil is required, the method is extremely economical. Thermal contact resistance measurements performed using MgO substrates demonstrate that this technique promotes thermal contact between the substrate and heater block comparable to silver paste. These measurements will be presented, along with a design for a fixture capable of holding wafers up to 0.75 inches in diameter.