Abstract: Recesses (46) are etched into the finished peripheral boundaries of a structure formed of a generally planar electronic circuit (40) on an upper surface (42) of a wafer (44). Bonding pads (48) are deposited in the recesses (46) and interconnected to the electronic circuit (40). External leads (52) are attached to the bonding pads (48), such that the external leads (52) lie below the plane of the electronic circuit (40).

Abstract: A microelectronic device is fabricated by furnishing a first substrate (40) having a silicon etchable layer (42), a silicon dioxide etch-stop layer (44) overlying the silicon layer (42), and a single-crystal silicon wafer (46) overlying the etch-stop layer (44), the wafer (46) having a front surface (52) not contacting the etch stop layer (44). A microelectronic circuit element (50) is formed in the single-crystal silicon wafer (46). The method further includes attaching the front surface (52) of the single-crystal silicon wafer (46) to a second substrate (58), and etching away the silicon layer (42) of the first substrate (40) down to the etch-stop layer (44). The second substrate (58) may also have a microelectronic circuit element (58') therein that can be electrically interconnected to the microelectronic circuit element (50).

Abstract: A microelectronic device is fabricated on a first substrate (40), and transferred to a second substrate (58). The first substrate (40) has a silicon etchable layer (42), a silicon dioxide etch-stop layer (44) overlying the etchable layer (42), and a single-crystal wafer (46) overlying the etch-stop layer (44). A microelectronic circuit element (48) is formed in the wafer (46) of the first substrate (40). The wafer (46) of the first substrate (40) is attached to an aluminum oxide temporary substrate (52), and the etchable layer (42) of the first substrate (40) is etched away down to the etch-stop layer (44) to leave a primary device structure. The etch-stop layer (44) may optionally be processed to remove all or a part of the layer. An exposed surface (56) of the primary device structure is fixed to the second substrate (58), and the temporary substrate (52) is removed.