What is claimed is:
1. A method for forming a spacer in a semiconductor device having a trench for formation of a gate electrode, the device comprising a pad oxide formed adjacent the trench, and a pad nitride on top of the pad oxide, the method comprising:
depositing a first conductive material onto a gate oxide layer formed within the trench and atop the pad nitride;
depositing a second conductive material atop the first conductive material;
planarizing the first and second conductive material to a level coplanar with the pad nitride;
removing the pad nitride;
etching the first conductive material to a predetermined depth within the trench to form a divot; and
forming an integrated spacer within the divot.
2. The method as in claim 1 wherein the trench is formed within a silicon substrate.
3. The method as in claim 1 wherein the first conductive material is comprised of polysilicon.
4. The method as in claim 1 wherein the first conductive material comprises polysilicon-germanium.
5. The method as in claim 1 wherein the conductive material has a thickness of about 200 to about 1000 angstroms.
6. The method as in claim 1 wherein the step of depositing the first and second conductive material and liner layer comprises chemical vapor deposition.
7. The method as in claim 1 wherein the step of planarizing the pad nitride comprises chemical mechanical polishing.
8. The method as in claim 1 wherein the step of planarizing the pad nitride comprises reactive ion etching.
9. The method as in claim 1 wherein the step of etching the first conductive material is accomplished by a process chosen from the group consisting of reactive ion etching, wet etch, and plasma etch.
10. The method as in claim 1 wherein the etching back of the liner layer is accomplished by a process chosen from the group consisting of reactive ion etching, wet etch, and plasma etch.
11. The method as in claim 10 wherein the wet etch utilizes NH4OH.
12. The method as in claim 1 wherein the conductive material is about 600 angstroms thick.
13. The method as in claim 1 wherein the first conductive material comprises tungsten or a tungsten alloy.
14. The method as in claim 1 wherein the step of etching the first conductive material to a predetermined depth within the trench is performed after the step of planarizing the first and second conductive material and before the step of removing the pad nitride.
15. The method as in claim 1 wherein the semiconductor device is a Dynamic Random Memory Access device.
16. A method of forming a memory device having a vertical array transistor whereby a gate electrode is formed within a trench, the transistor comprising a pad oxide formed adjacent the trench, and having a pad nitride on top of the pad oxide, the method comprising:
depositing a first conductive material onto a gate oxide layer formed within the trench and atop the pad nitride;
depositing a second conductive material onto the first conductive material to form the gate electrode, the second conductive material having selective etch properties relative the first conductive material;
planarizing the first and second conductive material to a level coplanar with a top surface of the pad nitride;
removing the pad nitride;
etching the first conductive material to a predetermined depth within the trench to form a divot; and
depositing a liner layer within the divot, whereby a spacer is formed within the divot;
depositing a second liner layer;
depositing an array top oxide on top of the second liner layer;
planarizing the array top oxide to a level coplanar to the top of the second liner layer;
removing the second liner layer;
forming gate conductors atop the polysilicon gate electrode and the array top oxide; and
forming sidewall spacers at each side of the gate conductors.
17. The method of claim 16 wherein the memory device is Dynamic Random Access Memory device.
18. The method of claim 16 wherein the first conductive material comprises polysilicon and the second conductive material comprises polysilicon-germanium.
19. The method of claim 16 wherein the second liner layer is comprised of silicon nitride.
20. A vertical gate transistor comprising:
a trench formed in a top surface of a substrate;
a gate oxide formed along a sidewall of the trench;
a gate electrode formed within the trench and extending above the top surface of the substrate, the gate electrode comprising a first material being relatively non-reactive to a first etchant substantially surrounded by a second material being relatively reactive to said first etchant;
a divot formed within the second material extending a predetermined distance below the top surface of the substrate;
a liner layer formed within the divot;
at least one doped region adjacent the trench at the top surface of the substrate;
a first conductor contacting the gate electrode; and
a second conductor contacting the at least one doped region.
21. The vertical gate transistor of claim 20 wherein the first material is polysilicon and the second material is polysilicon-germanium.
22. The vertical gate transistor of claim 20 wherein the liner layer is silicon nitride.
23. The vertical gate transistor of claim 20 wherein the first etchant is NH4OH.
24. The vertical gate transistor of claim 20 further comprising a second doped region adjacent the trench and being formed below the top surface of the substrate.
25. The vertical gate transistor of claim 20 further comprising a trench capacitor formed within the trench.
26. The vertical gate transistor of claim 20 wherein the predetermined distance is within the range of 200 to 800 angstroms.
The claims below are in addition to those above.
All refrences to claims which appear below refer to the numbering after this setence.
1. A ligator apparatus comprising in combination:
A. a ligator barrel assembly (i) having a ligating barrel end opposite a cord penetrating barrel end and (ii) including:
a. an outer barrel mounted about at least a portion of an inner barrel, the inner barrel being rotatable with respect to the outer barrel; and
b. a cord channel penetrating the outer periphery of the outer barrel and having a first cord passage and second cord passage extending from the outer periphery of the outer barrel to the inner periphery of the outer barrel; and
B. an activating cord penetrating the cord-penetrating barrel end, the first cord passage, and the second cord passage and having an inner barrel activation end abutting the inner barrel.
2. The ligator of claim 1 wherein the outer barrel has interior threads matably engaging exterior threads on the inner barrel.
3. The ligator of claim 1 wherein the cord channel includes an angled section at a 20-90 degree angle to the axis of the inner barrel.
4. The ligator of claim 2 wherein the cord channel includes an angled section at a 20-90 degree angle to the axis of the inner barrel, the angled section terminating in the second cord passage.
5. The ligator of claim 3 wherein the cord channel includes an arcuate section.
6. The ligator of claim 4 wherein the cord channel is includes an arcuate section having angled section.
7. The ligator of claim 1 wherein the angled section is at a 60-90 degree angle to the axis of the inner barrel.
8. The ligator of claim 2 wherein the angled section is at a 60-90 degree angle to the axis of the inner barrel.
9. The ligator of claim 7 wherein the cord channel includes an arcuate section.
10. The ligator of claim 8 wherein the cord channel includes an arcuate section having angled section.
11. The ligator of claim 1 wherein the inner barrel activation end of the activating cord wraps around the outer periphery of the inner barrel.
12. The ligator of claim 2 wherein the inner barrel activation end of the activating cord wraps around the outer periphery of the inner barrel.
13. The ligator of claim 8 wherein the inner barrel activation end of the activating cord wraps around the outer periphery of the inner barrel.
14. The ligator of claim 10 wherein the inner barrel activation end of the activating cord wraps around the outer periphery of the inner barrel.
15. The ligator of claim 1 wherein the inner barrel includes a viewing passage through the ligator.
16. The ligator of claim 2 wherein the inner barrel includes a viewing passage through the ligator.
17. The ligator of claim 8 wherein the inner barrel includes a viewing passage through the ligator.
18. The ligator of claim 10 wherein the inner barrel includes a viewing passage through the ligator.
19. The ligator of claim 11 wherein the inner barrel includes a viewing passage through the ligator.
20. The ligator of claim 14 wherein the inner barrel includes a viewing passage through the ligator.
21. A ligator apparatus comprising in combination:
A. a ligator barrel assembly (i) having a ligating barrel end opposite a cord penetrating barrel end and (ii) including:
a. an outer barrel mounted about at least a portion of an inner barrel providing a ligator viewing passage through the ligator barrel assembly;
b. a cord channel penetrating the outer periphery of the outer barrel and having a first cord passage and second cord passage extending from the outer periphery of the outer barrel to the inner periphery of the outer barrel; and
B. an activating cord penetrating the cord-penetrating barrel end, the first cord passage, and the second cord passage and having an inner barrel activation end abutting the inner barrel.
22. The ligator apparatus of claim 21 wherein the ligator barrel assembly includes an endoscope mounting section providing a mounting section viewing passage through the endoscope mounting section.
23. The ligator apparatus of claim 21 wherein the inner barrel is laterally movably mounted in the ligator barrel assembly with respect to the outer barrel.
24. The ligator apparatus of claim 22 wherein the inner barrel is laterally movably mounted in the ligator barrel assembly with respect to the outer barrel.
25. The ligator apparatus of claim 21 wherein the inner barrel is rotatably mounted in the ligator barrel assembly with respect to the outer barrel.
26. The ligator apparatus of claim 22 wherein the inner barrel is rotatably mounted in the ligator barrel assembly with respect to the outer barrel.
27. The ligator apparatus of claim 24 wherein the inner barrel is rotatably mounted in the ligator barrel assembly with respect to the outer barrel.
28. The ligator apparatus of claim 26 further comprising: (C) an activating cord pulling assembly mountable at a fixed distance from the ligator barrel assembly.
29. The ligator apparatus of claim 26 further comprising: (C) an activating cord pulling assembly having an endoscope mount mountable adjacent a working channel access passage in an endoscope.
30. The ligator apparatus of claim 29 where in the activating cord pulling assembly includes a rotatable cord wrap rod.
31. The ligator apparatus of claim 30 wherein the activating cord pulling assembly includes a cord wrap indexing handle connected to the rotatable cord wrap rod.
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