Abstract: A process for forming a junction-isolated, electrically conductive via in a silicon substrate and a conductive apparatus to carry electrical signal from one side of a silicon wafer to the other side are provided. The conductive via is junction-isolated from the bulk of the silicon substrate by diffusing the via with a dopant that is different than the material of the silicon substrate. Several of the junction-isolated vias can be formed in a silicon substrate and the silicon wafer coupled to a second silicon substrate comprised of a device that requires electrical connection. This process for forming junction-isolated, conductive vias is simpler than methods of forming metallized vias, especially for electrical devices more tolerant of both resistance and capacitance.

Abstract: A piezoresistive device senses mechanical input and converts mechanical movement of at least two relatively movable parts into an electrical output. An SOI substrate is provided. A gap extends across a portion of the substrate. The gap defines the at least two relatively moveable parts and a flexible cross-section that connects the at least two relatively moveable parts. The cross-section is made of a same material as the substrate. At least one strain sensitive element is at a surface of the substrate. The at least one strain sensitive element has two end portions interconnected by an intermediate neck portion. The neck portion is supported on a structure that concentrates strain. The structure extends across the gap and has vertical walls extending to the cross-section in the gap. The structure is made of the same material as the substrate.

Abstract: A piezoresistive device is provided for sensing mechanical input and converts mechanical movement of at least two relatively movable parts into an electrical output. A silicon substrate is provided that is oriented in the (100) plane and has an n-type impurity. A gap extends across a portion of the substrate. The gap defines the at least two relatively moveable parts. A flexible cross-section connects the at least two relatively moveable parts. The cross-section is made of the same material as the substrate. At least one strain sensitive element is provided on a surface of the silicon substrate, is aligned in a [110] direction and includes a p-type impurity. The strain sensitive element has two end portions interconnected by an intermediate neck portion. The neck portion is supported on a structure that concentrates strain. The structure extends across the gap and has vertical walls that extend to the cross-section in the gap. The structure is made of the same material as the substrate.