Patent ID: 7084449
Filing Date: 2006-08-01
Classification: H01L

Abstract:
1. A microelectronic element, comprising: a first trench disposed within a substrate; a second trench disposed within the substrate, each of the first and second trenches having a sidewall extending along a region of single-crystal semiconductor material in the substrate, and each of the first and second trenches being elongated in a direction extending downwardly from a major surface of the substrate; a first dielectric collar extending downwardly along the sidewall of the first trench to a first depth below the major surface of the substrate, the first dielectric collar for reducing parasitic capacitance along an upper portion of the first trench; a first capacitor extending from the first dielectric collar at the first depth downwardly along the single-crystal semiconductor region along the sidewall of the first trench; a second dielectric collar extending downwardly along the sidewall of the second trench to a second depth deeper below the major surface of the substrate than the first depth, the second dielectric collar for reducing parasitic capacitance along an upper portion of the second trench; a second capacitor extending from the second dielectric collar at the second depth downwardly along the single-crystal semiconductor region along the sidewall of the second trench, such that a top of the first capacitor is disposed at the first depth from the major surface, and a top of the second capacitor is disposed at the second depth from the major surface.