the bottom plate still in single crystal silicon or in polysilicon examples of capacitors formed in trenches and recesses are described in u s pat no 4 467 450 issued aug 21 1984 and u s pat no 4 651 184 issued mar 17 1987 both assigned to texas instruments incorporated referring to fig6 a trench capacitor is shown where the lower plate is region 30 disposed in the sidewalls of a trench etched into substrate 2 silicon nitride layer 6 and yttrium oxide layer 8 are disposed over lower plate 30 as before with the upper plate 10 disposed in the trench to complete the capacitor further alternatives not shown incorporating a trench or recess include a polysilicon lower plate such as shown in fig5 disposed within a trench or recess as shown in fig6 with the layered film and upper plate disposed thereover and also include a pillar capacitor where an isolation region is disposed at the bottom of the trench with the capacitor lower plate disposed on the sides of the mesa defined by the trench it is believed that the layered film of the invention will provide equivalent improvements in such structures as provided in the planar.