Structure and fabrication method for capacitors integratible with vertical replacement gate transistors
View Patent ↗A process and an architecture related to a vertical MOSFET device and a capacitor for use in integrated circuits. Generally, the integrated circuit structure includes a semiconductor layer with a major surface formed along a plane thereof and further including a first doped region formed in the surface. A second doped region of a different conductivity type than the first doped region is positioned over the first region. A third doped region of a different conductivity type than the second region is positioned over the second region. In one embodiment of the invention, a semiconductor device includes a first layer of semiconductor material and a first field-effect transistor having a first source/drain region formed in the first layer. A channel region of the transistor is formed over the first layer and an associated second source/drain region is formed over the channel region. The integrated circuit further includes a capacitor having a bottom plate, dielectric layer and a top capacitor plate. In an associated method of manufacture, a first device region, selected from the group consisting of the source region and a drain region of a field-effect transistor is formed on a semiconductor layer. A first field-effect transistor gate region is formed over the first device region. A capacitor comprising top and bottom layers with a dielectric layer disposed therebetween, is also formed on the semiconductor layer. In another embodiment, the capacitor layers are formed within a trench or window formed in the semiconductor layer.
1. An integrated circuit structure comprising:
first and second areas;
a semiconductor layer having a major surface formed along a plane in first and second areas;
a first doped region of a first conductivity type in the first area of the integrated circuit structure;
multiple layers over the first doped region in the first area of the integrated circuit structure, wherein the multiple layers have a window therein extending to the first doped region;
a second doped region of a second conductivity type in the window formed in the first area of the integrated circuit structure;
a third doped region of the first conductivity type over the second doped region;
a gate oxide adjacent the second doped region;
a first conductive layer comprising a first laterally disposed electrically continuous region in the first area of the integrated circuit structure and a second laterally disposed electrically continuous region in the second area of the integrated circuit structure, wherein the first laterally disposed electrically continuous region is adjacent the gate oxide in the first area of the integrated circuit structure, and wherein the second laterally disposed electrically continuous region is spaced apart from the gate oxide and in the second area of the integrated circuit structure and wherein the first and second laterally disposed electrically continuous regions are laterally separated by at least an insulating material that defines a separation between the first and second areas of the integrated circuit structure;
a first dielectric layer over the second laterally disposed electrically continuous region in the second area of the integrated circuit structure, wherein the first dielectric layer is laterally spaced apart, and separate from the gate oxide;
a second conductive layer over the first dielectric layer and
wherein the second laterally disposed electrically continuous region in the second area of the integrated circuit structure, the first dielectric layer and the second conductive layer form a capacitor and wherein the first laterally disposed electrically continuous region in the first area of the integrated circuit structure is interposed between the first dielectric region and the gate oxide.
2. The integrated circuit structure of claim 1 wherein the first doped region is a first source/drain region of a MOSFET, the second doped region is a channel region of the MOSFET, and the third doped region is a second source/drain region of the MOSFET.
3. The integrated circuit structure of claim 2 wherein the first laterally disposed electrically continuous region in the first area of the integrated circuit structure comprises a gate of the MOSFET and wherein the second laterally disposed electrically continuous region in the second area of the integrated circuit structure comprises a bottom plate of the capacitor.