Process for making planarized silicon fin device
AssigneeInternational Business Machines Corporation
InventorsK. Paul L. Muller, Edward J. Nowak, Hon-Sum P. Wong
Life of this patent
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Abstract
An improved fin device used as the body of a field effect transistor (“FET”) and an improved process of making the fin device. The fin device allows for the fabrication of very small dimensioned metal-oxide semiconductor (“MOS”) FETs in the size range of micrometers to nanometers, while avoiding the typical short channel effects often associated with MOSFETs of these dimensions. Accordingly, higher density MOSFETs may be fabricated such that more devices may be placed on a single semiconductor wafer. The process of making the fin device results in an improved fully planarized device.
Claims28
A process for fabricating a fin device as the body for a field effect transistor, comprising the steps of
- (a) forming a vertical semiconductor-on-insulator fin on a substrate with an oxide layer on top of a segment of said fin;
- (b) depositing a polysilicon layer;
- (c) forming a source and a drain separated by a polysilicon channel on top of the oxide layer that is on top of the segment of the fin;
- (d) depositing a silicide layer over the exposed polysilicon layer;
- (e) depositing an oxide layer over the fin;
- (f) polishing the oxide layer;
- and
- (g) implanting dual workfunction elements into the top of the polished oxide layer.
A process for fabricating a fin device, comprising the steps of:
- (a) depositing a dielectric on a substrate;
- (b) etching the dielectric to form a vertical fin;
- (c) sequentially depositing a nitride composition layer and an oxide composition layer;
- (d) etching the oxide layer to expose a section of the fin;
- (e) etching the nitride layer from the exposed section of the fin;
- (f) depositing a polysilicon layer;
- (g) polishing the polysilicon layer and fin to a selected fin height;
- (h) removing the oxide layer and the nitride layer;
- (i) depositing an oxide layer;
- (j) implanting dual channel elements;
- (k) depositing a polysilicon layer and a nitride layer;
- (l) etching selectively the nitride layer and polysilicon layer to form a halo over the fin;
- (m) implanting a source and a drain onto the halo;
- (n) etching the oxide layer;
- (o) depositing a polysilicon layer;
- (p) polishing the polysilicon layer to planarize the polysilicon layer with nitride layer;
- (q) etching the polysilicon layer;
- (r) depositing sequentially a silicide layer and an oxide layer;
- (s) polishing the oxide layer to planarize the oxide layer and nitride layer;
- (t) etching the nitride layer to expose the polysilicon layer between the source and drain;
- (u) implanting workfunction elements into the oxide layer on either side of the fin;
- (v) forming a silicide layer between the source and drain;
- (w) depositing an oxide layer;
- (x) polishing the oxide layer to form a planar surface;
- and
- (y) forming dual contacts in the device.
A planarized fin device, comprising:
- a substrate;
- a vertical fin formed on a portion of the substrate, leaving a remaining portion of the substrate exposed;
- an oxide layer covering the fin and the exposed substrate;
- a source and drain formed on top of the oxide layer;
- a polysilicon halo separating the source and drain;
- a silicide layer covering the polysilicon layer;
- a top oxide layer;
- and
- dual workfunction implants positioned within the top oxide layer and forming, with the top oxide layer, a planarized top surface of the fin device.
Dependencies are inferred from the claim text.