Process for forming an electronic device including semiconductor fins
View Patent ↗An electronic device can include a base layer, a semiconductor layer, and a first semiconductor fin spaced apart from and overlying a semiconductor layer. In a particular embodiment, a second semiconductor fin can include a portion of the semiconductor layer. In another aspect, a process of forming an electronic device can include providing a workpiece that includes a base layer, a first semiconductor layer that overlies and is spaced apart from a base layer, a second semiconductor layer that overlies, and an insulating layer lying between the first semiconductor layer and the second semiconductor layer. The process can also include removing a portion of the second semiconductor layer to form a first semiconductor fin, and forming a conductive member overlying the first semiconductor fin.
1. A process for forming an electronic device comprising:
providing a workpiece including a base layer, a first semiconductor layer that overlies and is spaced apart from the base layer, a second semiconductor layer, and an insulating layer lying between the first semiconductor layer and the second semiconductor layer;
forming a first opening in the insulating layer extending to the first semiconductor layer, wherein the insulating layer lies between the first and second semiconductor layers;
epitaxially growing a third semiconductor layer from the first semiconductor layer after forming the first opening;
removing a portion of the second semiconductor layer to form a first semiconductor fin that overlies and is spaced apart from the first semiconductor layer, and removing a portion of the third semiconductor layer to form a second semiconductor fin that is spaced apart from the first semiconductor fin, wherein:
before removing the portion of the second semiconductor layer and removing the portion of the third semiconductor layer, top surfaces of the second and third semiconductor layers lie along a same plane; and
removing the portion of the second semiconductor layer and removing the portion of the third semiconductor layer are performed substantially simultaneously during at least one point in time;
forming a first gate electrode overlying the first semiconductor fin; and
doping portions of the first semiconductor fin to form first source/drain regions entirely within the first semiconductor fin, wherein a first transistor includes the first semiconductor fin, the first gate electrode, and the first source/drain regions.
2. The process of claim 1 , further comprising polishing an exposed surface of the third semiconductor layer, such that after polishing, top surfaces of the second and third semiconductor layers lie substantially along a same plane.
3. The process of claim 2 , wherein removing the portion of the second semiconductor layer comprises removing portions of the first and third semiconductor layers to form a third semiconductor fin that includes portions of the first and third semiconductor layers.
4. The process of claim 3 , further comprising:
forming a second gate electrode overlying the third semiconductor fin; and
doping portions of the third semiconductor fin to form second source/drain regions entirely within the third semiconductor layer, wherein a second transistor includes the third semiconductor fin, the second gate electrode, and the second source/drain regions.
5. The process of claim 1 , further comprising forming a first source/drain region and a second source/drain region spaced apart from the first source/drain region, wherein:
a channel region lies within the first semiconductor fin;
the channel region is configured, such that when the transistor would be on, charge carriers would flow through the channel region in a direction substantially parallel to a primary surface of the base layer; and
forming the first gate electrode includes forming a first gate electrode having portions that lie adjacent to opposing sides of the first semiconductor fin.
6. The process of claim 1 , further comprising forming a second transistor, wherein:
the second transistor is a planar transistor and includes a channel region; and
top surfaces of the first semiconductor fin and the channel region of the second transistor lie substantially along a same plane.
7. The process of claim 1 , further comprising:
forming a second gate electrode overlying the second semiconductor fin; and
doping portions of the second semiconductor fin to form second source/drain regions, wherein a second transistor includes the second semiconductor fin, the second gate electrode, and the second source/drain regions.
8. The process of claim 7 , wherein the second semiconductor layer and the third semiconductor layer have different crystal orientations.
9. The process of claim 7 , wherein the second semiconductor layer and the third semiconductor layer have different strains.
10. The process of claim 9 , wherein the second semiconductor layer and the third semiconductor layer have different compositions of semiconductor elements.
11. The process of claim 7 , wherein:
removing the portion of the second semiconductor layer exposes a portion of the insulating layer; and
the process further comprises removing a portion of the first semiconductor layer to expose a portion of another insulating layer that lies between the base layer and the first semiconductor layer, wherein the second semiconductor fin includes parts of the first and third semiconductor layers.
12. The process of claim 11 , wherein forming the first gate electrode and forming the second gate electrode comprises:
forming a conductive layer over the first semiconductor fin and the second semiconductor fin, wherein after forming the conductive layer, a thickness of the conductive layer is less than each of a height of the first semiconductor fin and a height of the second semiconductor fin; and
etching the conductive layer to form the first gate electrode for the first transistor and the second gate electrode for the second transistor.
13. The process of claim 12 , wherein doping the portions of the second semiconductor fin to form the second source/drain regions is performed such that the second source/drain regions lie entirely within the second semiconductor fin.
14. The process of claim 13 , further comprising
forming a second opening in the insulating layer and first semiconductor layer extending to the base layer;
epitaxially growing a fourth semiconductor layer from the base layer after forming the second opening;
forming a third gate electrode over the fourth semiconductor layer; and
doping portions of the fourth semiconductor layer to form third source/drain regions entirely within the fourth semiconductor layer, wherein a third transistor includes the third gate electrode and the third source/drain regions.
15. The process of claim 14 , wherein the third transistor is a planar transistor, and doping portions of the fourth semiconductor layer are performed such that the third source/drain regions lie entirely within the fourth semiconductor layer.
16. The process of claim 14 , further comprising removing a portion of the fourth semiconductor layer to form a third semiconductor fin that overlies the base semiconductor layer; wherein doping portions of the fourth semiconductor layer is performed such that the third source/drain regions lie entirely within the third semiconductor fin.
17. A process for forming an electronic device comprising:
providing a workpiece including a base layer, a first semiconductor layer that overlies and is spaced apart from the base layer, a second semiconductor layer, and an insulating layer lying between the first semiconductor layer and the second semiconductor layer;
removing a portion of the second semiconductor layer to form a first semiconductor fin that overlies and is spaced apart from the first semiconductor layer;
forming a first opening in the insulating layer extending to the first semiconductor layer, wherein the insulating layer lies between the first and second semiconductor layers;
epitaxially growing a third semiconductor layer from the first semiconductor layer after forming the first opening;
removing a portion of the third semiconductor layer to form a second semiconductor fin that is spaced apart from the first semiconductor fin;
forming a second opening in the insulating layer and the first semiconductor layer extending to the base layer;
epitaxially growing a fourth semiconductor layer from the base layer after forming the second opening;
forming a first gate electrode overlying the first semiconductor fin;
forming a second gate electrode overlying the second semiconductor fin;
forming a third gate electrode over the fourth semiconductor layer;
doping portions of the first semiconductor fin to form first source/drain regions entirely within the first semiconductor fin, wherein a first transistor includes the first semiconductor fin, the first gate electrode, and the first source/drain regions;
doping portions of the second semiconductor fin to form second source/drain regions entirely within the third semiconductor layer, wherein a second transistor includes the second semiconductor fin, the second gate electrode, and the second source/drain regions; and
doping portions of the fourth semiconductor layer to form third source/drain regions entirely within the fourth semiconductor layer; wherein a third transistor includes the third gate electrode and the third source/drain regions.
18. The process of claim 17 , wherein the second transistor is a planar transistor.
19. The process of claim 17 , further comprising removing a portion of the fourth semiconductor layer to form a third semiconductor fin that overlies the base semiconductor layer.