Methods for selective deposition using a sacrificial capping layer
Methods and systems for selectively depositing a p-type doped silicon germanium layer and structures and devices including a p-type doped silicon germanium layer are disclosed. An exemplary method includes providing a substrate, comprising a surface comprising a first area comprising a first material and a second area comprising a second material, within a reaction chamber; depositing a p-type doped silicon germanium layer overlying the surface, the p-type doped silicon germanium layer comprising gallium; and depositing a cap layer overlying the p-type doped silicon germanium layer. The method can further include an etch step to remove the cap layer and the p-type doped silicon germanium layer overlying the second material.
1. A selective deposition method comprising the steps of:
providing a substrate, comprising a surface comprising a first area comprising a first material and a second area comprising a second material, within a reaction chamber;
depositing a p-type doped silicon germanium layer overlying the surface, the p-type doped silicon germanium layer comprising at least one of boron or gallium;
depositing a cap layer overlying the p-type doped silicon germanium layer, the cap layer comprising silicon; and,
etching the cap layer and the p-type doped silicon germanium layer overlying the second material;
wherein the steps of depositing the p-type doped silicon germanium layer, depositing the cap layer and the etching are performed in the same reaction chamber; and,
wherein the steps of depositing the p-type doped silicon germanium layer, depositing the cap layer, and the etching are repeated 1 to about 500 times;
thereby selectively depositing the p-type doped silicon germanium layer on the first area.
2. The method of claim 1 , wherein the step of etching comprises providing a halide gas to the reaction chamber.
3. The method of claim 2 , wherein the halide gas is selected from the group consisting of hydrogen chloride and chlorine.
4. The method of claim 1 , wherein the first material comprises semiconductor material.
5. The method of claim 1 , wherein the first material comprises silicon.
6. The method of claim 1 , wherein the second material comprises a dielectric material.
7. The method of claim 6 , wherein the dielectric material is selected from the group consisting of oxides, nitrides, and oxynitrides.
8. The method of claim 1 , wherein the step of depositing a p-type doped silicon germanium layer does not include exposing the surface to a gas comprising a halide.
9. The method of claim 1 , wherein the steps of depositing a p-type doped silicon germanium layer and depositing a cap layer are performed in the same reaction chamber.