We claim:
1. A method for making a local interconnect structure for an integrated circuit comprising:
providing a semiconductor substrate;
forming a Ti layer having a nitrogen-rich upper portion, the Ti layer overlying a portion of the semiconductor substrate;
forming a refractory metal layer on the Ti layer;
forming a Si layer on the refractory metal layer;
removing a portion of the Si layer; and
heating to form the local interconnect structure.
2. The method of claim 1, wherein the semiconductor substrate is a silicon substrate.
3. The method of claim 2, wherein the Ti layer is formed over active areas in the silicon substrate.
4. The method of claim 1, wherein the nitrogen-rich region extends along an upper surface of the Ti layer.
5. The method of claim 1, wherein the lower portion of the Ti layer contains substantially no nitrogen.
6. The method of claim 1, including forming the Ti layer by sputter depositing Ti in an atmosphere comprising nitrogen.
7. The method of claim 1, including forming the Ti layer by depositing Ti and then rapid thermal annealing in an atmosphere comprising nitrogen.
8. The method of claim 1, including forming the Ti layer by depositing Ti and then implanting nitrogen ions into the upper portion of the Ti.
9. The method of claim 1, wherein the thickness of the nitrogen-rich upper-portion ranges from about 50 to about 100 .
10. The method of claim 1, wherein the thickness of the Ti layer ranges from about 100 to about 300 .
11. The method of claim 1, wherein the concentration of nitrogen in the nitrogen-rich upper-portion ranges from about 2% to about 15%.
12. The method of claim 7, further comprising performing the rapid thermal annealing at about 400 C. to about 600 C. for about 15 to about 90 seconds.
13. The method of claim 1, wherein the refractory metal layer comprises Co or Ti.
14. The method of claim 13, wherein the refractory metal comprises Ti.
15. The method of claim 1, further comprising forming the refractory metal layer by vapor deposition or sputter deposition.
16. The method of claim 15, further comprising sputtering the refractory metal layer.
17. The method of claim 1, wherein the thickness of the refractory metal layer ranges from about 100 to about 300 .
18. The method of claim 1, wherein the thickness of the silicon layer ranges from about 400 to about 1000 .
19. The method of claim 1, wherein the Si layer is amorphous.
20. The method of claim 1, further comprising removing the portion of the Si layer by patterning and etching.
21. The method of claim 1, wherein the heating is a rapid thermal process.
22. The method of claim 1, including removing those portions of the Ti layer not underlying the local interconnect.
23. The method of claim 22, including removing the portions of the Ti layer using a wet etch solution.
24. The method of claim 23, wherein the wet etch solution comprises H2O, H2O2, and NH4OH.
25. A source structure for a local interconnect, comprising:
a semiconductor substrate;
a Ti layer having a nitrogen-rich upper portion, the Ti layer overlying a portion of the substrate;
a refractory metal layer overlying the Ti layer; and
a silicon layer overlying the refractory metal layer.
26. The structure of claim 25, wherein the semiconductor substrate is a silicon substrate.
27. The structure of claim 26, wherein the Ti layer is disposed over active areas in the silicon substrate.
28. The structure of claim 25, wherein the nitrogen-rich upper-portion extends along an upper surface of the Ti layer.
29. The structure of claim 25, wherein the lower portion of the Ti layer contains substantially no nitrogen.
30. The structure of claim 25, wherein the thickness of the nitrogen-rich upper-portion ranges from about 50 to about 100 .
31. The structure of claim 25, wherein the thickness of the Ti layer ranges from about 100 to about 300 .
32. The structure of claim 25, wherein the concentration of nitrogen in the nitrogen-rich upper-portion ranges from about 2% to about 15%.
33. The structure of claim 25, wherein the refractory metal layer comprises Co or Ti.
34. The structure of claim 33, wherein the refractory metal comprises Ti.
35. The structure of claim 25, wherein the thickness of the refractory metal layer ranges from about 100 to about 300 .
36. The structure of claim 25, wherein the thickness of the silicon layer ranges from about 400 to about 1000 .
37. A local interconnect structure, comprising:
a semiconductor substrate;
a titanium silicide layer disposed over a portion of the substrate;
a nitrogen-rich Ti layer disposed over the titanium silicide layer; and
a refractory-metal silicide layer disposed on the nitrogen-rich Ti layer.
38. The structure of claim 37, wherein the semiconductor substrate is a silicon substrate.
39. The structure of claim 38, wherein the titanium silicide layer is disposed over active areas in the silicon substrate.
40. The structure of claim 37, wherein the thickness of the nitrogen-rich Ti layer ranges from about 50 to about 100 .
41. The structure of claim 37, wherein the concentration of nitrogen in the nitrogen-rich Ti layer ranges from about 2% to about 15%.
42. The structure of claim 37, wherein the refractory metal layer comprises Co or Ti.
43. The structure of claim 42, wherein the refractory metal comprises Ti.
44. The structure of claim 37, wherein the thickness of the refractory-metal silicide layer ranges from about 300 to about 1000 .
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 hand-held setting tool comprising an actuation switch (13); connection means (16) for connecting the setting tool (10) to a positioning device (20) and having a counter-coupling element (18) for the positioning device (20); a structural component (33); and a mechanical switching link (30) including at least one first switching element (34) displaceable in the structural component (33) along a longitudinal axis (A) of the setting tool (10) for connecting an actuation element provided on the positioning device (20) with the actuation switch (13); and a safety device (50) for preventing actuation of the actuation switch (13) at an orientation other than a predetermined orientation of the setting tool (10) and including at least three separate channels (56), at least three blocking members (55a, 55b, 55c) displaceable in the at least three separate channels (56) respectively, and a recess (51) provided on the first switching element (34) for receiving the blocking members (55a, 55b, 55c) and which opens toward the structural component (33),
wherein the at least three channels (56) are inclined with respect to a plane (E) extending perpendicular to the longitudinal axis (A), and
wherein the at least three channels (56) intersect, in some regions, an axial projection of the first switching element (34) in the form of a secant and are open toward the first switching element (34) in respective overlapping regions (59).
2. A setting tool according to claim 1, wherein the at least three channels (56) are distributed about the longitudinal axis (A) rotationally symmetrically.
3. A setting tool according to claim 1, wherein the blocking members (55a, 55b, 55c) are pin-shaped.
4. A setting tool according to claim 1, wherein the first switching element (34) is rod-shaped and is displaceable in a guide channel formed in the structural component (33).
5. A setting tool according to claim 1, wherein the at least three channels (56) are inclined to the plane (E) each at an angle (\u03b1) between 20\xb0 and 50\xb0.
6. A setting tool according to claim 1, wherein the overlapping region (59) of each channel (56) with respect to the axial projection of the first switching element (34) on the longitudinal axis (A) has a depth (T) smaller than a diameter (D) of the channel (56).
7. A setting tool according to claim 1, wherein the recess (51) in the first switching element (34) is formed as an annular groove closed at opposite axial ends thereof.
8. A setting tool according to claim 1, wherein the recess (51) has walls (52) that limit the recess (51) in an axial direction and that are inclined to the longitudinal axis (A) so that an axial width of the recess (51) diminishes from a radially outer side to radially inner side.