Semiconductor device having germanium active layer with underlying parasitic leakage barrier layer

A non-planar semiconductor device, comprising:

• a first buffer layer disposed above a substrate;
• a parasitic leakage barrier disposed above the first buffer layer;
• a second buffer layer disposed above the parasitic leakage barrier;
• a three-dimensional germanium active layer disposed above the second buffer layer;
• gate electrode stack disposed on and completely surrounding the three-dimensional germanium active layer;
• a bottom gate insulating (BGI) structure disposed between the parasitic leakage barrier and a bottom portion of the gate electrode stack;
• and
• source and drain regions disposed above the parasitic leakage barrier, on either side of the gate electrode stack.

A semiconductor device, comprising:

• a vertical arrangement of one or more germanium nanowires disposed above a substrate;
• a first buffer layer disposed above the substrate;
• a parasitic leakage barrier disposed above the first buffer layer;
• wherein a bottom-most germanium nanowire is disposed above the parasitic leakage layer;
• a gate electrode stack disposed on and at least partially surrounding the bottom-most germanium nanowire of the one or more germanium nanowires, and disposed on and completely surrounding remaining of the one or more germanium nanowires;
• and
• source and drain regions disposed in each germanium nanowire, on either side of the gate electrode stack.

A planar semiconductor device, comprising:

• a first buffer layer disposed on a substrate, wherein the substrate consists essentially of silicon and the first buffer layer comprises silicon germanium;
• a parasitic leakage barrier disposed on the first buffer layer;
• a second buffer layer disposed on the parasitic leakage barrier, the second buffer layer comprising silicon germanium having a higher concentration of germanium than the first buffer layer, wherein the parasitic leakage barrier comprises alternating first and second layer types, the first layer types consisting essentially of silicon or of silicon germanium having a lower concentration of germanium than the first or second buffer layers, and the second layer types comprising essentially the same material as the first buffer layer;
• a germanium active layer disposed on the second buffer layer, wherein the germanium active layer consists essentially of germanium;
• a gate electrode stack disposed on the germanium active layer;
• and
• source and drain regions disposed above the parasitic leakage barrier, on either side of the gate electrode stack.

A planar semiconductor device, comprising:

• a first buffer layer disposed on a substrate, wherein the substrate consists essentially of silicon and the first buffer layer comprises silicon germanium;
• a parasitic leakage barrier disposed on the first buffer layer;
• a second buffer layer disposed on the parasitic leakage barrier, the second buffer layer comprising silicon germanium having a higher concentration of germanium than the first buffer layer, wherein the parasitic leakage barrier comprises alternating first and second layer types, the first layer types consisting essentially of silicon or of silicon germanium having a lower concentration of germanium than the first or second buffer layers, and the second layer types comprising essentially the same material as the second buffer layer;
• a germanium active layer disposed on the second buffer layer, wherein the germanium active layer consists essentially of germanium;
• a gate electrode stack disposed on the germanium active layer;
• and
• source and drain regions disposed above the parasitic leakage barrier, on either side of the gate electrode stack.

A non-planar semiconductor device, comprising:

• a first buffer layer disposed on a substrate, wherein the substrate consists essentially of silicon and the first buffer layer comprises silicon germanium;
• a parasitic leakage barrier disposed on the first buffer layer;
• a second buffer layer disposed on the parasitic leakage barrier, wherein the second buffer layer comprises silicon germanium having a higher concentration of germanium than the first buffer layer, and wherein the parasitic leakage barrier comprises alternating first and second layer types, the first layer types consisting essentially of silicon or of silicon germanium having a lower concentration of germanium than the first or second buffer layers, and the second layer types comprising essentially the same material as the first buffer layer;
• a three-dimensional germanium active layer disposed above the second buffer layer, wherein at least a portion of the three-dimensional germanium active layer is disposed on the second buffer layer, and wherein the three-dimensional germanium active layer consists essentially of germanium;
• a gate electrode stack disposed on and at least partially surrounding the three-dimensional germanium active layer;
• and
• source and drain regions disposed above the parasitic leakage barrier, on either side of the gate electrode stack.

A non-planar semiconductor device, comprising:

• a first buffer layer disposed on a substrate, wherein the substrate consists essentially of silicon and the first buffer layer comprises silicon germanium;
• a parasitic leakage barrier disposed on the first buffer layer;
• a second buffer layer disposed on the parasitic leakage barrier, wherein the second buffer layer comprises silicon germanium having a higher concentration of germanium than the first buffer layer, and wherein the parasitic leakage barrier comprises alternating first and second layer types, the first layer types consisting essentially of silicon or of silicon germanium having a lower concentration of germanium than the first or second buffer layers, and the second layer types comprising essentially the same material as the second buffer layer;
• a three-dimensional germanium active layer disposed above the second buffer layer, wherein at least a portion of the three-dimensional germanium active layer is disposed on the second buffer layer, and wherein the three-dimensional germanium active layer consists essentially of germanium;
• a gate electrode stack disposed on and at least partially surrounding the three-dimensional germanium active layer;
• and
• source and drain regions disposed above the parasitic leakage barrier, on either side of the gate electrode stack.