Abstract: A low cost highly integrated method of fabricating a heat sink on the backside of a power semiconductor device maintains device performance, improves thermal transfer, and enables reliable planar connections without having to dice the wafer or package the discrete device-heat sink assembly. An etch stop layer is formed between the wafer and the frontside power devices to protect them during backside processing and to reduce the contact resistance between the device and its heat sink. The heat sinks are formed by thinning, patterning and then plating the wafer in such a manner that the devices can be released without dicing. The heat sinks are preferably oversized so that a vacuum tool can grasp the heat sink from above without damaging the device and then compression bond the heat sink onto a planar microstrip circuit assembly, which is designed and packaged to facilitate easy replacement of failed devices.

Abstract: A method for producing topographic projections, especially useful for producing many small projections of less than about 100 &mgr;m in diameter and in height. This method is useful for making contact pads of membrane probes used to test integrated circuits and spacers of liquid crystal light valves.

Abstract: A low cost highly integrated method of fabricating a heat sink on the backside of a power semiconductor device maintains device performance, improves thermal transfer, and enables reliable planar connections without having to dice the wafer or package the discrete device-heat sink assembly. An etch stop layer is formed between the wafer and the frontside power devices to protect them during backside processing and to reduce the contact resistance between the device and its heat sink. The heat sinks are formed by thinning, patterning and then plating the wafer in such a manner that the devices can be released without dicing. The heat sinks are preferably oversized so that a vacuum tool can grasp the heat sink from above without damaging the device and then compression bond the heat sink onto a planar microstrip circuit assembly, which is designed and packaged to facilitate easy replacement of failed devices.

Abstract: A method for fabricating resilient z-axis contacts to electrically interconnect IC wafers or MCMs in 3-D integrated circuits uses photolithography to provide larger carrier sizes, higher contact densities by decreasing the spacing, smaller contact footpads, and precise control of the contact's shape and position. The contacts are fabricated by forming photoresist patterns on the carrier's top and bottom surfaces that are initially rectangular, and then reflowing the photoresist materials to provide smooth surfaces suitable for forming the metal contacts, and depositing metal layers over the respective patterns. Second photoresist patterns are formed over respective metal layers to conform with the contact's shape, the metal is etched away according to the pattern, and the photoresists are removed such that the remaining metalization forms a resilient z-axis contact that is attached to the carrier and extends therefrom with a predetermined shape.