Excimer laser assisted deposition of metal films on aluminum nitride

Aluminum nitride (AlN) is a high thermal conductivity ceramic substrate for microelectronics with a better thermal coefficient of expansion match to silicon than traditional aluminum oxide substrates. Metallization techniques are needed to increase the ease of use of AlN as a substrate for high power circuits, high frequency devices, and multichip modules. Excimer laser assisted deposition of copper and aluminum addresses the need for repair and customization of interconnects, as well as a patterning technique for defining circuit features without photolithography. In the work reported here, a KrF (248) laser system with motion control states, vacuum chamber, and heated stage has been used to decompose AlN to an aluminum rich metallic seed layer for laser induced chemical vapor deposition and electroless copper plating.