Patent ID: 7256439

Claim:
A structure including a plurality of trench capacitors, comprising: a substrate including a single-crystal semiconductor region; a plurality of trenches in said single-crystal semiconductor region arranged in an array including a first dummy trench of said plurality of trenches defining a first peripheral edge of said array, a second dummy trench of said plurality of trenches defining a second peripheral edge of said array remote from said first peripheral edge, and a plurality of third trenches between said first and second dummy trenches, said array having a lateral dimension extending between said first and second peripheral edges; a plurality of trench capacitors, each having a node dielectric layer extending along a wall of a trench of said plurality of trenches, said plurality of trench capacitors having node dielectric layers along walls of said third trenches having a first circuit function, and each of said trench capacitors having node dielectric layers along walls of said first and second dummy trenches not having said first circuit function; a continuous buried plate diffusion region serving as a common capacitor plate belonging to all of said plurality of trench capacitors, said buried plate diffusion region having a lateral dimension equal to or larger than a lateral dimension of said array; an isolation region overlying a portion of said buried plate diffusion region and overlying at least said first dummy trench, said isolation region not overlying said third trenches; a doped well region laterally adjacent to said isolation region, said doped well region extending downwardly from a major surface of said single-crystal semiconductor region to a depth below a top level of said buried plate diffusion region at which said doped well region merges with said buried plate diffusion region; and a contact in conductive communication with said doped well region such that said doped well region provides a conductive path between said contact and said buried plate diffusion region for maintaining a common potential on said common capacitor plate belonging to all of said plurality of trench capacitors.