SBFET transistor and corresponding fabrication process
A process for manufacturing a Schottky barrier field-effect transistor is provided. The process includes: providing a structure including a control gate and a semiconductive layer positioned under the gate and having protrusions that protrude laterally with respect to the gate; anisotropically etching at least one of the protrusions by using the control gate as a mask, so as to form a recess in this protrusion, this recess defining a lateral face of the semiconductive layer; depositing a layer of insulator on the lateral face of the semiconductive layer; and depositing a metal in the recess on the layer of insulator so as to form a contact of metal/insulator/semiconductor type between the deposit of metal and the lateral face of the semiconductive layer.
1. A process for manufacturing a Schottky barrier field-effect transistor, comprising steps of:
providing a structure comprising a control gate and a semiconductive layer positioned under the control gate and having protrusions that protrude laterally beyond sides of the control gate;
anisotropically etching at least one of said protrusions by using the control gate as a mask, so as to form a recess in the at least one protrusion, the recess defining at least one lateral face of said semiconductive layer disposed laterally beyond the sides of the control gate;
depositing a layer of insulator on said at least one lateral face of said semiconductive layer; and
depositing a metal on the layer of insulator in the recess so as to form a contact of metal/insulator/semiconductor type between the metal and said at least one lateral face of said semiconductive layer.
2. The process for manufacturing a Schottky barrier field-effect transistor according to claim 1 , wherein a height of said formed contact of the metal/insulator/semiconductor type is at least equal to 6 nm on said at least one lateral face of the semiconductive layer.
3. The process for manufacturing a Schottky barrier field-effect transistor according to claim 1 , further comprising steps of:
anisotropically etching another of said protrusions by using the control gate as a mask, so as to form another recess in the another protrusion, the another recess defining another lateral face of said semiconductive layer disposed laterally beyond the sides of the control gate;
depositing the layer of insulator on said another lateral face of said semiconductive layer; and
depositing the metal on the layer of insulator in the another recess of said another protrusion so as to form another contact of metal/insulator/semiconductor type between the metal and said another lateral face of said semiconductive layer.
4. The process for manufacturing a Schottky barrier field-effect transistor according to claim 3 , wherein a geometric plane passes under the control gate, passes through said deposited metal, passes through said deposited layers of insulator, and passes through an area of the semiconductive layer.
5. The process for manufacturing a Schottky barrier field-effect transistor according to claim 1 , wherein a thickness of said deposited layer of insulator is between 0.5 nm and 3 nm and separates the metal from said semiconductive layer.
6. The process for manufacturing a Schottky barrier field-effect transistor according to claim 1 , wherein said deposited layer of insulator includes a material chosen from among the group comprising TiO 2 , ZnO, ITO, BaTiO 3 , Si 3 N 4 , and Al 2 O 3 .
7. The process for manufacturing a Schottky barrier field-effect transistor according to claim 1 , wherein said deposited metal includes a metal chosen from among the group comprising Ti, TiN, Zr, Hf, Pt, and Au.
8. The process for manufacturing a Schottky barrier field-effect transistor according to claim 1 , wherein said control gate comprises a gate metal and a gate insulator positioned under and on sides of said gate metal.
9. The process for manufacturing a Schottky barrier field-effect transistor according to claim 1 , wherein said at least one lateral face of said semiconductive layer is formed in the at least one protrusion having an implantation of dopants.
10. The process for manufacturing a Schottky barrier field-effect transistor according to claim 9 , wherein the at least one protrusion has a doping concentration of at least equal to 10 19 cm −3 .
11. The process for manufacturing a Schottky barrier field-effect transistor according to claim 1 , further comprising forming an insulating spacer on the sides of the control gate and plumb with said deposited metal.
12. The process for manufacturing a Schottk bairier field-effect transistor according to claim 11 , wherein the layer of insulator is also deposited on a lateral face of the sides of the control gate, said insulating spacer being formed on the layer of insulator deposited on the lateral face of the sides of the control gate.
13. The process for manufacturing a Schottky barrier field-effect transistor according to claim 11 , wherein said insulating spacer is formed plumb with the metal deposited in said recess.
14. The process for manufacturing a Schottky barrier field-effect transistor according to claim 1 ,
wherein the depositing the layer of insulator further comprises depositing the layer of insulator on an upper surface of the recess in the at least one protrusion, and
wherein the deposited layer of insulator prevents the deposited metal from physically contacting the semiconductive layer in the recess.