DIRECT BONDING OF COPPER TO ALUMINUM NITRIDE

Direct bonding (DB) of copper to aluminum nitride was studied. The pro cess parameters of DB were optimized based on time, temperature and th ickness of the Cu-foil for Cu-Al2O3 system in an N-2 atmosphere contai ning 500 ppm O-2 in a temperature range of 1065 to 1075 degrees C. The se conditions were then applied to the Cu-AlN system. Wettability of A lN by Cu was studied and improved through oxidation of AlN and modific ation of Cu by adding 1 at.% O-2 The interface of AIN and Cu containin g O-2 was then simulated using powder mixtures. The oxidation of AlN w as found to be the driving force for improving the wettability of the AlN by copper. The activation energy for oxidation of AIN was found to be 94 kJ mol(-1). It was demonstrated that direct bonding of Cu to AI N can be performed without any intermediate layer. The average peel st rength of AlN-Cu, Al2O3-Cu and AlN-Al2O3-Cu systems were 42, 49 and 14 .7 MPa, respectively.