Patent ID: 9425154
Filing Date: 2016-08-23
CPC Classification: H01L

Claim Text:
1. A method comprising: forming a first guard ring around a circuit region on a first side of a substrate, the first guard ring comprising a doped region of the substrate, the first guard ring having a first conductivity type, the circuit region having a second conductivity type; forming a first isolation trench around the circuit region on the first side of the substrate; forming through vias, the through vias extending through the first isolation trench to a second side of the substrate; forming a second guard ring encircling the first guard ring, wherein the through vias are laterally between the first guard ring and the second guard ring, the second guard ring having the first conductivity type; and forming a conductive layer over the second side of the substrate, the conductive layer being electrically coupled to the through vias, the conductive layer being over substantially an entirety of the second side of the substrate opposite of the circuit region.