Robert Forrest Kwasnick

Method for fabricating high density ultrasound array

A high yield method of fabricating an ultrasound array having densely packed ultrasound elements with smooth surface finishes includes the steps of: 1) applying an acoustic matching material to opposites faces (or surfaces) of a piezo electric material ceramic block; 2) cutting the block in a plane perpendicular to the two faces of the block so as to form a plurality of wafers having the acoustic matching material disposed on opposite ends; 3) assembling the wafers to form a laminated body having respective portions of the matching layer on opposite surfaces and with the wafers each being separated from an adjacent wafer by a selected gap distance and bonded together by a polymeric adhesive material; 4) cutting the laminated body along a longitudinal axis so as to form a first laminate body subassembly and a second laminate body subassembly, each of the subassemblies having a front surface having the acoustic matching material disposed thereon and a back surface where the laminate body was cut; 5) applying a backing layer to each laminate body subassembly; and 6) removing the polymeric adhesive material disposed between the wafers, whereby each subassembly comprises an ultrasound array having transducer elements separated by the selected array gap distance.

Buried-oxide isolation with etch-stop (BOXES)

A buried-oxide (BOX) isolation process which has greatly improved submicrometer MOS manufacturability has been developed. The process, BOXES (BOX with etch-stop) isolation, incorporates an etch-stop layer over active area down to which the field oxide is etched, rather than to the active-area surface as in BOX. Nonuniformities inherent to the BOX process do not then cause the field oxide to be recessed below the active area surface. Furthermore, by a brief overetch of etch-stop during its patterning, the field oxide is made to controllably encroach laterally over the active-area edges. Measurements of NMOS devices demonstrate that BOXES isolation with lateral encroachment has greatly reduced sidewall and edge parasitic conduction.<<ETX>>