Patent ID: 6537921
Filing Date: 2003-03-25
Classification: H01L

Abstract:
A method of forming a diode comprising:a) providing a semiconductor body of a first conductivity type having a layer of a second conductivity type on a first surface thereof; b) forming a plurality of cylindrical oxide pedestals on the layer of a second conductivity type; c) directionally etching to form trenches in the layer of second conductivity type between pedestals; d) forming regions of the first conductivity type in the layer of second conductivity type between pedestals and extending somewhat under the pedestals; e) directionally etching to form deeper trenches extending through the layer of second conductivity type between pedestals and to remove the regions of the first conductivity type in the layer of second conductivity type between pedestals and not the part of the layer of second conductivity type extending somewhat under the pedestals; f) depositing a gate oxide; g) depositing a heavily doped polysemiconductor layer; h) directionally etching the polysemiconductor layer to remove the polysemiconductor from the gate oxide between pedestals; i) implanting to convert the regions between pedestals from the first conductivity type to the second conductivity type; j) directionally etching to further reduce the height of the polysemiconductor layer on the gate oxide on the side walls of the pedestals to a level of the remainder of the layer of d) above; k) removing the exposed gate oxide; l) depositing a conductive layer as a first electrical contact to the diode; and, m) providing an electrical contact to the semiconductor body as a second electrical contact to the diode.