Hybrid orientation substrate with stress layer
View Patent ↗A hybrid orientation substrate includes a base substrate having a first orientation, a first surface layer having a first orientation disposed on the base substrate in a first region, and a second surface layer disposed on the base substrate in a second region. The second surface layer has an upper sub-layer having a second orientation, and a lower sub-layer between the base substrate and the upper sub-layer. The lower sub-layer having a first stress induces a second stress on the upper sub-layer.
1. A method of fabricating a hybrid orientation substrate comprising the steps of:
providing a substrate comprising
a first region; the first region having a first surface layer having a first substrate orientation,
a second region; the second region having a second surface layer having a second substrate orientation, the first and second regions are electrically isolated by an isolation region,
the second surface layer comprising a plurality of sub-layers over the second region, wherein the plurality of sub-layers comprise an upper sub-layer comprising a semiconductor material having a second crystal orientation over a lower sub-layer comprising a first and a second pad buried layers sandwiching a stress layer having a neutral or moderate tensile stress; and
converting the stress layer to a high tensile stress layer, wherein converting the stress layer comprises subjecting the substrate to an ultra violet (UV) treatment.
2. The method of claim 1 wherein the first and second pad buried layers serve to improve adhesion between the stress layer and the substrate.
3. The method of claim 1 wherein the second pad buried layer serves as a buffer to avoid direct contact between the stress layer and the substrate.
4. A method of fabricating a hybrid orientation substrate comprising the steps of:
providing a substrate comprising
a first region; the first region having a first surface layer having a first substrate orientation,
a second region; the second region having a second surface layer having a second substrate orientation, the first and second regions are electrically isolated by an isolation region,
the second surface layer comprises a stress layer over the second region, wherein the stress layer is formed below a semiconductor material having a second crystal orientation and comprises a composite sub-layer having a plurality of buried layers, the stress layer having a neutral or moderate tensile stress; and
subjecting the substrate to an ultra violet (UV) treatment to convert the stress layer to a high tensile stress layer.
5. The method of claim 4 wherein the UV treatment is conducted at about 400-500° C. for about 10-15 mins.
6. The method of claim 4 wherein the plurality of buried layers comprise a first pad buried layer and a second pad buried layer sandwiching the stress layer.
7. The method of claim 6 wherein the second pad buried layer serves as a buffer to avoid direct contact between the stress layer and the substrate.
8. The method of claim 1 wherein the UV treatment is conducted at about 400-500° C. for about 10-15 mins.
9. A method of fabricating a hybrid orientation substrate comprising the steps of:
providing a surface substrate comprising
a first region having a first layer with a first substrate orientation,
a second region having a second layer with a second substrate orientation, the first and second regions are electrically isolated by an isolation region, wherein the second layer comprises a semiconductor material having a second crystal orientation formed over a stress layer comprising a composite layer having a plurality of buried layers, the stress layer having a neutral or moderate tensile stress over it;
bonding the surface substrate to a base substrate, wherein the base substrate has the same substrate orientation as the first layer; and
converting the stress layer of the second region to a high tensile stress layer, wherein converting the stress layer comprises subjecting the substrate to an ultra violet (UV) treatment.
10. The method of claim 9 wherein the stress layer comprises silicon nitride .
11. The method of claim 9 wherein the UV treatment is conducted at about 400-500° C. for about 10-15 mins.
12. The method of claim 9 wherein the second region comprises an upper or first sub-layer and a lower or second sub-layer.
13. The method of claim 12 wherein the lower or second sub-layer comprises the stress layer.
14. The method of claim 9 wherein the plurality of buried layers comprise a first pad buried layer and a second pad buried layer sandwiching the stress layer.
15. The method of claim 13 wherein the stress layer comprises a first stress which induces a second stress on the upper or first sub-layer.
16. The method of claim 15 wherein the stress layer comprises a tensile stress material which induces a compressive stress on the upper or first sub-layer.