1. A field effect transistor structure comprising:
a semiconductor layer having end portions and a center portion between said end portions, said center portion having an area that extends laterally beyond said end portions and said center portion comprising:
a channel region between said end portions, said channel region being doped with a first conductivity type dopant such that said channel region has a first conductivity type; and
a gate-to-body tunnel current region in said area that extends laterally beyond said end portions, said gate-to-body tunnel current region comprising:
a first implant region immediately adjacent to said channel region and doped with said first conductivity type dopant at a higher concentration than said channel region;
a second implant region adjacent to said first implant region and doped with a second conductivity type dopant different from said first conductivity type dopant such that said second implant region has a second conductivity type different from said first conductivity type; and
an enhanced generation and recombination region at a junction between said first implant region and said second implant region; and
a gate structure traversing said center portion.
2. The field effect transistor of claim 1, said enhanced generation and recombination region comprising a third implant region overlapping said first implant region and said second implant region.
3. The field effect transistor of claim 1, said enhanced generation and recombination region comprising a metal layer extending vertically between said first implant region and said second implant region.
4. The field effect transistor structure of claim 1, said gate structure comprising: a gate dielectric layer on a top surface of said semiconductor layer, said gate dielectric layer comprising:
a first dielectric section above said second implant region and said enhanced generation and recombination region of said gate-to-body tunnel current region; and
a second dielectric section above said first implant region of said gate-to-body tunnel current region and above said channel region, said first dielectric section and said second dielectric section having any of different thicknesses and different dielectric constants.
5. The field effect transistor structure of claim 4, said gate structure comprising a gate conductor layer, having different sections with different work functions, on said gate dielectric layer above said channel region and said gate-to-body tunnel current region, respectively.
6. The field effect transistor structure of claim 4, said gate structure comprising a gate conductor layer comprising a first conductive section above said gate-to-body tunnel current region and having said first conductivity type and a second conductive section above said channel region and having said second conductivity type.
7. The field effect transistor of claim 1, further comprising a trench isolation structure laterally surrounding said semiconductor layer such that said trench isolation structure is positioned laterally immediately adjacent to three sides of said area that extends laterally beyond said end portions.
8. A field effect transistor structure comprising:
a semiconductor layer having end portions and a center portion between said end portions, said center portion having an area that extends laterally beyond said end portions and said center portion comprising:
a channel region between said end portions, said channel region being doped with a first conductivity type dopant such that said channel region has a first conductivity type; and
a gate-to-body tunnel current region in said area that extends laterally beyond said end portions, said gate-to-body tunnel current region comprising:
a first implant region immediately adjacent to said channel region and doped with said first conductivity type dopant at a higher concentration than said channel region;
a second implant region adjacent to said first implant region and doped with a second conductivity type dopant different from said first conductivity type dopant such that said second implant region has a second conductivity type different from said first conductivity type; and
an enhanced generation and recombination region at a junction between said first implant region and said second implant region; and
a gate structure traversing said center portion, said gate structure comprising a gate conductor layer comprising:
a first conductive section above said gate-to-body tunnel current region and having said first conductivity type; and
a second conductive section positioned laterally adjacent to said first conductive section above said channel region and having said second conductivity type.
9. The field effect transistor of claim 8, said enhanced generation and recombination region comprising a third implant region overlapping said first implant region and said second implant region.
10. The field effect transistor of claim 8, said enhanced generation and recombination region comprising a metal layer extending vertically between said first implant region and said second implant region.
11. The field effect transistor structure of claim 8, said gate structure further comprising a gate dielectric layer between said center portion and said gate conductor layer.
12. The field effect transistor of claim 11, said gate dielectric layer comprising:
a first dielectric section above said second implant region and said enhanced generation and recombination region of said gate-to-body tunnel current region; and
a second dielectric section above said first implant region of said gate-to-body tunnel current region and above said channel region, said first dielectric section and said second dielectric section having any of different thicknesses and different dielectric constants.
13. The field effect transistor of claim 8, further comprising a trench isolation structure laterally surrounding said semiconductor layer such that said trench isolation structure is positioned laterally immediately adjacent to three sides of said area that extends laterally beyond said end portions.
14. A method of forming a field effect transistor structure, said method comprising:
providing a semiconductor layer doped with a first conductivity type dopant such that said semiconductor layer has said first conductivity type, said semiconductor layer further having end portions and a center portion between said end portions, and said center portion having an area that extends laterally beyond said end portions;
forming a gate-to-body tunnel current region in said area that extends laterally beyond said end portions, said forming of said gate-to-body tunnel current region comprising:
forming a first implant region in said area immediately adjacent to a designated channel region in said center portion between said end portions, said first implant region being doped with said first conductivity type dopant at a higher concentration than said channel region;
forming a second implant region adjacent to said first implant region, said second implant region being doped with a second conductivity type dopant different from said first conductivity type dopant such that said second implant region has a second conductivity type different from said first conductivity type; and
forming an enhanced generation and recombination region at a junction between said first implant region and said second implant region; and
forming a gate structure traversing said center portion.
15. The method of claim 14, said forming of said enhanced generation and recombination region comprising forming a third implant region overlapping said first implant region and said second implant region.
16. The method of claim 14, said forming of said enhanced generation and recombination region comprising:
after said forming of said first implant region and said second implant region, forming an opening in said semiconductor layer extending vertically through said junction between said first implant region and said second implant region; and
forming a metal layer in said opening.
17. The method of claim 14, said forming of said gate structure comprising forming a gate dielectric layer on a top surface of said semiconductor layer, said forming of said gate dielectric layer comprising:
forming a first dielectric section above said second implant region and said enhanced generation and recombination region of said gate-to-body tunnel current region; and
forming a second dielectric section above said first implant region of said gate-to-body tunnel current region and above said channel region, said first dielectric section being different from said second dielectric section.
18. The method of claim 17, said first dielectric section and said second dielectric section being formed so as to have any of different thicknesses and different dielectric constants.
19. The method of claim 17, said forming of said gate structure comprising forming a gate conductor layer on said gate dielectric layer such that said gate conductor layer comprises different sections with different work functions above said gate-to-body tunnel current region and above said channel region.
20. The method of claim 17, said forming of said gate structure comprising forming a gate conductor layer on said gate dielectric layer such that said gate conductor layer comprises:
a first conductive section above said gate-to-body tunnel current region and having said first conductivity type; and
a second conductive section above said channel region and having said second conductivity type.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A steering apparatus comprising: a steering shaft which is formed of a shaft section and a yoke section; an inner column which supports the steering shaft via a bearing; an outer column which embraces the inner column and which has an embracing inner circumferential surface with a same diameter along an axial direction; a fixing bracket which has fixing side sections sandwiching both sides of the outer column in a width direction; and a tightener which tightens and releases the outer column together with the fixing bracket, wherein the inner column has an embraced cylindrical section that is embraced by the outer column, a relief section having an outer diameter formed smaller than other portions of the embraced cylindrical section is formed in a middle region in the axial direction of the embraced cylindrical section, and the bearing that pivotally supports the steering shaft is fixed to an inner circumferential side of the relief section.
2. The steering apparatus according to claim 1, wherein both sides of the relief section in the axial direction are arranged as conical slope sections.
3. The steering apparatus according to claim 1, wherein the relief section is formed at a position of the embraced cylindrical section toward the front in the axial direction, and the front of the relief section in the axial direction constitutes a yoke housing cylindrical section that houses the yoke section of the steering shaft.
4. The steering apparatus according to claim 1, wherein a telescoping-enabling long hole is formed in the embraced cylindrical section, and a knock pin that protrudes from the embracing inner circumferential surface is mounted on the outer column and inserted into the telescoping-enabling long hole.
5. The steering apparatus according to claim 2, wherein the relief section is formed at a position of the embraced cylindrical section toward the front in the axial direction, and the front of the relief section in the axial direction constitutes a yoke housing cylindrical section that houses the yoke section of the steering shaft.
6. The steering apparatus according to claim 2, wherein a telescoping-enabling long hole is formed in the embraced cylindrical section, and a knock pin that protrudes from the embracing inner circumferential surface is mounted on the outer column and inserted into the telescoping-enabling long hole.
7. The steering apparatus according to claims 3, wherein a telescoping-enabling long hole is formed in the embraced cylindrical section, and a knock pin that protrudes from the embracing inner circumferential surface is mounted on the outer column and inserted into the telescoping-enabling long hole.
8. The steering apparatus according to claim 5, wherein a telescoping-enabling long hole is formed in the embraced cylindrical section, and a knock pin that protrudes from the embracing inner circumferential surface is mounted on the outer column and inserted into the telescoping-enabling long hole.