1. A nonvolatile memory cell comprising:
a source region and a drain region formed in a semiconductor substrate and spaced apart from each other;
a source selection line and a drain selection line disposed over the semiconductor substrate between the source region and the drain region, the source selection line and the drain selection line being adjacent to the source region and the drain region, respectively;
a cell gate pattern disposed over the semiconductor substrate between the source selection line and the drain selection line;
a first floating impurity region provided in the semiconductor substrate under a gap region between the source selection line and the cell gate pattern; and
a second floating impurity region provided in the semiconductor substrate under a gap region between the drain selection line and the cell gate pattern,
wherein distances between the cell gate pattern and the selection lines are less than widths of the selection lines.
2. The nonvolatile memory cell according to claim 1, wherein the cell gate pattern comprises a floating gate, an inter-gate insulating layer and a word line pattern, and each of the selection lines comprises a single conductive layer.
3. The nonvolatile memory cell according to claim 2, wherein the word line pattern comprises a word line and a capping layer pattern, and the floating gate is self-aligned with the word line and the capping layer pattern to have substantially the same width as the word line and the capping layer pattern.
4. The nonvolatile memory cell according to claim 2, wherein the word line pattern comprises:
a word line and a capping layer pattern; and
word line spacers covering sidewalls of the word line and sidewalls of the capping layer pattern,
wherein the floating gate is self-aligned with the word line spacers to be wider than the word line and the capping layer pattern.
5. The nonvolatile memory cell according to claim 1, further comprising main spacers covering sidewalls of the selection lines and sidewalls of the cell gate pattern,
wherein the main spacers include first main spacers filling gap regions between the selection lines and the cell gate pattern as well as second main spacers disposed adjacent to the source and drain regions.
6. The nonvolatile memory cell according to claim 5, wherein the source region comprises a lightly doped source region disposed under the second main spacer on the sidewall of the source selection line and a heavily doped source region contacting the lightly doped source region, and the drain region comprises a lightly doped drain region disposed under the second main spacer on the sidewall of the drain selection line and a heavily doped drain region contacting the lightly doped drain region,
wherein the first and second floating impurity regions have substantially the same impurity concentration as the lightly doped source and drain regions.
7. The nonvolatile memory cell according to claim 5, further comprising sidewall capping layers interposed between the floating gate and the first main spacers and between the selection lines and the second main spacers.
8. The nonvolatile memory cell according to claim 1, further comprising:
a first hard mask pattern on the source selection line; and
a second hard mask pattern on the drain selection line.
9. The nonvolatile memory cell according to claim 1, further comprising:
an interlayer insulating layer disposed on the substrate having the cell gate pattern and the selection lines; and
a bit line disposed on the interlayer insulating layer and electrically connected to the drain region,
wherein the bit line is disposed to cross over the cell gate pattern and the selection lines.
10. The nonvolatile memory cell according to claim 1, further comprising:
a tunnel insulating layer interposed between the cell gate pattern and the semiconductor substrate; and
a gate insulating layer interposed between the selection lines and the semiconductor substrate,
wherein the tunnel insulating layer and the gate insulating layer are comprised of the same material layer.
11. A method of fabricating a nonvolatile memory cell, comprising:
forming a preliminary gate pattern on a semiconductor substrate;
forming an inter-gate insulating layer pattern and a word line pattern which are stacked on the preliminary gate pattern;
forming first sacrificial spacers on both sidewalls of the word line pattern;
etching the preliminary gate pattern using the first sacrificial spacers and the word line pattern as etch masks to form a gate pattern;
removing the first sacrificial spacers;
forming first and second hard mask patterns on both ends of the gate pattern respectively, the first and second hard mask patterns being formed substantially parallel to the word line pattern; and
etching the gate pattern using the word line pattern and the hard mask patterns as etch masks to form a floating gate, a source selection line and a drain selection line under the word line pattern, the first hard mask pattern and the second hard mask pattern, respectively,
wherein the floating gate, the inter-gate insulating layer pattern and the word line pattern constitute a cell gate pattern.
12. The method according to claim 11, further comprising forming a tunnel insulating layer on the semiconductor substrate prior to formation of the preliminary gate pattern.
13. The method according to claim 11, wherein the preliminary gate pattern is formed of a polysilicon layer.
14. The method according to claim 11, wherein the forming of the inter-gate insulating layer pattern and the word line pattern comprises:
forming an inter-gate insulating layer, a control gate conductive layer and a capping layer on the substrate having the preliminary gate pattern; and
patterning the capping layer, the control gate conductive layer and the inter-gate insulating layer to form an inter-gate insulating layer pattern, a word line and a capping layer pattern.
15. The method according to claim 14, further comprising forming word line spacers on sidewalls of the word line and sidewalls of the capping layer pattern.
16. The method according to claim 14, wherein the capping layer is formed by stacking a main capping layer and a sacrificial capping layer.
17. The method according to claim 16, wherein the main capping layer is formed of an insulating layer having an etch selectivity with respect to the preliminary gate pattern, and the sacrificial capping layer is formed of an insulating layer having an etch selectivity with respect to the main capping layer.
18. The method according to claim 11, wherein the first sacrificial spacers are formed of a silicon nitride layer.
19. The method according to claim 11, wherein the forming of the first and second hard mask patterns comprises:
forming second sacrificial spacers on sidewalls of the word line pattern and sidewalls of the gate pattern after removal of the first sacrificial spacers, the second sacrificial spacers being formed to have a width less than the width of the first sacrificial spacers to expose top surfaces of both ends of the gate pattern;
thermally oxidizing the substrate having the second sacrificial spacers to form thermal oxide layers on the exposed ends of the gate pattern; and
removing the second sacrificial spacers.
20. The method according to claim 19, wherein the second sacrificial spacers are formed of an oxidation resistant material layer.
21. The method according to claim 20, wherein the oxidation resistant material layer is a silicon nitride layer.
22. The method according to claim 11, further comprising forming impurity regions in the semiconductor substrate,
wherein the impurity regions are formed to have floating impurity regions in the semiconductor substrate between the cell gate pattern and the selection lines as well as a source region and a drain region adjacent to the source selection line and the drain selection line, respectively.
23. The method according to claim 11, further comprising implanting impurity ions into the semiconductor substrate using the cell gate pattern and the selection lines as ion implantation masks to form floating impurity regions under gap regions between the cell gate pattern and the selection lines as well as a lightly doped source region and a lightly doped drain region adjacent to the source selection line and the drain selection line, respectively.
24. The method according to claim 23, further comprising:
forming main spacers to cover sidewalls of the selection lines and sidewalls of the cell gate pattern, the main spacers being formed to include first main spacers filling the gap regions between the cell gate pattern and the selection lines as well as second main spacers formed adjacent to the lightly doped source and drain regions, respectively; and
implanting impurity ions into the semiconductor substrate using the cell gate pattern, the selection lines and the main spacers as ion implantation masks to form a heavily doped source region and a heavily doped drain region.
25. The method according to claim 24, further comprising forming a sidewall capping layer on sidewalls of the floating gate and sidewalls of the selection lines prior to formation of the main spacers.
26. The method according to claim 25, wherein the sidewall capping layer is formed of a thermal oxide layer.
27. The method according to claim 22, further comprising:
forming an interlayer insulating layer on the substrate having the impurity regions; and
forming a bit line on the interlayer insulating layer,
wherein the bit line is electrically connected to the drain region through a bit line contact hole passing through the interlayer insulating layer.
28. A method of fabricating a nonvolatile memory device, comprising:
forming an isolation layer in a predetermined region of a semiconductor substrate to define a plurality of parallel active regions;
forming a tunnel insulating layer on the active regions;
forming a gate conductive layer on the substrate having the tunnel insulating layer;
patterning the gate conductive layer to form a preliminary gate pattern having openings that expose predetermined regions of the isolation layer between the active regions;
forming an inter-gate insulating layer pattern and a word line pattern which are stacked on the substrate having the preliminary gate pattern, the word line pattern being formed across the active regions and the openings;
forming first sacrificial spacers on both sidewalls of the word line pattern, the first sacrificial spacers being formed to cover the openings that exist at both sides of the word line pattern;
etching the preliminary gate pattern using the first sacrificial spacers and the word line pattern as etch masks to form a gate pattern;
removing the first sacrificial spacers;
forming first and second hard mask patterns on both ends of the gate pattern, respectively, the first and second hard mask patterns being formed to be substantially parallel to the word line pattern; and
etching the gate pattern using the word line pattern and the first and second hard mask patterns as etch masks, thereby forming a plurality of floating gates overlapping the active regions under the word line pattern as well as a source selection line and a drain selection line crossing over the active regions under the first and second hard mask patterns, respectively,
wherein the floating gates, the inter-gate insulating layer pattern and the word line pattern constitute a cell gate pattern.
29. The method according to claim 28, wherein the gate conductive layer is formed of a polysilicon layer.
30. The method according to claim 28, wherein the forming of the inter-gate insulating layer pattern and the word line pattern comprises:
forming an inter-gate insulating layer, a control gate conductive layer and a capping layer on the substrate having the preliminary gate pattern; and
patterning the capping layer, the control gate conductive layer and the inter-gate insulating layer to form an inter-gate insulating layer pattern, a word line and a capping layer pattern.
31. The method according to claim 30, further comprising forming word line spacers on sidewalls of the word line and the capping layer pattern.
32. The method according to claim 30, wherein the capping layer is formed by stacking a main capping layer and a sacrificial capping layer.
33. The method according to claim 32, wherein the main capping layer is formed of an insulating layer having an etch selectivity with respect to the preliminary gate pattern, and the sacrificial capping layer is formed of an insulating layer having an etch selectivity with respect to the main capping layer.
34. The method according to claim 28, wherein the first sacrificial spacers are formed of a silicon nitride layer.
35. The method according to claim 28, wherein forming the first and second hard mask patterns comprises:
forming second sacrificial spacers on the sidewalls of the word line pattern and sidewalls of the gate pattern after removal of the first sacrificial spacers, the second sacrificial spacers being formed to have a width less than the width of the first sacrificial spacers, thereby exposing top surfaces of both ends of the gate pattern;
thermally oxidizing the substrate having the second sacrificial spacers to form thermal oxide layers on the exposed ends of the gate pattern; and
removing the second sacrificial spacers.
36. The method according to claim 35, wherein the second sacrificial spacers are formed of an oxidation resistant material layer.
37. The method according to claim 28, further comprising forming impurity regions in the semiconductor substrate,
wherein the impurity regions are formed to include floating impurity regions in the semiconductor substrate between the cell gate pattern and the selection lines as well as a source region and a drain region adjacent to the source selection line and the drain selection line, respectively.
38. The method according to claim 37, further comprising:
forming an interlayer insulating layer on the substrate having the impurity regions; and
forming a bit line on the interlayer insulating layer,
wherein the bit line is electrically connected to the drain region through a bit line contact hole passing through the interlayer insulating layer.
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 vehicle, comprising:
a. a body;
b. one or more driving appendages;
c. said driving appendages attached to said body to permit motion of said driving appendages to propel said body;
d. an actuation device; and
e. a drive train linking said actuation device to said driving appendages, said drive train comprising:
one or more couplings, said couplings comprising:
a) an input member, capable of cyclic motion;
b) an output member, capable of cyclic motion;
c) a torsionally compliant device unidirectionally biasing a relative phase of said input member and said output member;
d) said output member coupled to one of said driving appendages; and
e) said input member coupled to said actuation device.
2. The vehicle of claim 1, wherein said couplings include a limiting mechanism to limit said relative phasing to within a significant fraction of a cycle.
3. The vehicle of claim 1, further including a steering system.
4. The vehicle of claim 1, wherein said body comprises multiple body segments, and further includes a body flexion joint that connects said body segments and permits articulation of one body segment relative to another body segment, wherein said articulation is either:
a. actively controlled,
b. passively compliant, or
c. actively controlled and passively compliant.
5. The vehicle of claim 1, wherein said driving appendages are compliant.
6. The vehicle of claim 5, comprising at least two driving appendages.
7. The vehicle of claim 5, comprising at least three driving appendages.
8. The vehicle of claim 5, comprising at least four driving appendages.
9. The vehicle of claim 5, comprising at least six driving appendages.
10. The vehicle of claim 1, further including a foot with a means of passive traction on each of said driving appendages.
11. The vehicle of claim 1, wherein said motion is rotational.
12. The vehicle of claim 1, wherein said torsionally compliant device includes a spring.
13. The vehicle of claim 12, wherein said spring has a preload.
14. The vehicle of claim 1, wherein said actuation device includes a motor.
15. A vehicle, comprising:
a. a body;
b. one or more driving appendages, said driving appendages comprising;
1) a hub rotatably attached to said body and
2) one or more spoke extensions from said hub to propel said body;
c. an actuation device;
d. a drive train linking said actuation device to said driving appendages, said drive train comprising:
one or more rotary couplings, said rotary couplings comprising:
a) an input member;
b) an output member;
c) said input member and said output member rotatably attached;
d) a torsionally compliant device unidirectionally biasing a phase of said input member and said output member;
e) said output member coupled to one of said driving appendages; and
f) said input member coupled to said actuation device.
16. The vehicle of claim 15, wherein said rotary coupling includes a limiting mechanism to limit the relative phase of said input member and said output member to within a significant fraction of a cycle.
17. The vehicle of claim 16, wherein
a. said limiting mechanism includes a rotary mechanical stop and
b. said torsionally compliant device includes a torsional spring.
18. The vehicle of claim 15, further including a steering system.
19. The vehicle of claim 15, wherein said body comprises multiple body segments, and said body further includes a body flexion joint that connects said body segments and permits articulation, wherein said articulation is either:
a. actively controlled,
b. passively compliant, or
c. actively controlled and passively compliant.
20. The vehicle of claim 15, wherein said driving appendages are compliant.
21. The vehicle of claim 20, wherein the spoke extensions are compliant.
22. The vehicle of claim 15, further including a foot with a means of passive traction on each of said spoke extensions of each said driving appendage.
23. The vehicle of claim 15, wherein said driving appendages have at least two spoke extensions.
24. The vehicle of claim 15, wherein said driving appendages have at least three spoke extensions.
25. The vehicle of claim 15, wherein said driving appendages have at least four spoke extensions.
26. A vehicle, comprising:
a. a body;
b. one or more legs;
c. said legs attached to said body to permit motion;
d. an actuation device; and
e. a drive train linking said actuation device to said legs, said drive train comprising:
one or more couplings, said couplings comprising:
a) an input member, capable of cyclic motion;
b) an output member, capable of cyclic motion;
c) a torsionally compliant device unidirectionally biasing a relative phase of said input member and said output member;
d) said output member coupled to one of said legs; and
e) said input member coupled to said actuation device.
27. The vehicle of claim 26, wherein said couplings further include a limiting mechanism to limit said relative phasing of said input member and said output member to within a significant fraction of a cycle.
28. The vehicle of claim 26, further including a steering system.
29. The vehicle of claim 26, wherein said body comprises multiple body segments, and further includes a body flexion joint that connects said body segments and permits articulation, wherein said articulation is either:
a. actively controlled,
b. passively compliant, or
c. actively controlled and passively compliant.
30. The vehicle of claim 26, wherein said legs are compliant.
31. The vehicle of claim 26, further including a foot with a means of passive traction on each of said legs.
32. A drive system, comprising:
a drive member that provides a source of rotational powertorque;
a pair of unidirectionally pretensioned torsionally compliant devices, each coupled to receive rotational powertorque via the drive member; and
a pair of driving appendages, each coupled to a respective one of the torsionally compliant devices to rotate in response to the rotational powertorque provided by the respective torsionally compliant device;
wherein the torsionally compliant devices allow a phase angle change between the pair of driving appendages in response to a force or torque applied to at least one of the driving appendages.
33. The drive system of claim 32, wherein a motor provides the rotational powertorque to the drive member.
34. The drive system of claim 32, wherein the drive member includes an axle.
35. The drive system of claim 32, wherein the drive member includes at least two drive members, each coupled to provide powertorque to a respective torsionally compliant device.
36. The drive system of claim 32, wherein the pair of torsionally compliant devices have a selected preload.
37. The drive system of claim 36, wherein the pair of driving appendages are out of phase with one another when the selected preload of both of the torsionally compliant devices has not been overcome.
38. The drive system of claim 36, wherein one of the driving appendages is rotated relative to the other driving appendage when the selected preload of one of the respective torsionally compliant devices has been overcome.
39. The drive system of claim 36, wherein the pair of torsionally compliant devices have a positive stop limiting the phase angle change.
40. The drive system of claim 39, wherein the maximum phase angle change is based on the design of the driving appendages.
41. A vehicle comprising:
a frame;
a motor secured to the frame; and
a drive system in accordance with claim 32 secured to the frame and connected to the motor.
42. The vehicle of claim 41, comprising three drive systems.
43. The vehicle of claim 42, wherein the three drive systems are powered by a single motor.
44. The vehicle of claim 42, wherein the three drive systems are phased to employ an alternating tripod gait.
45. The vehicle of claim 44, wherein the individual driving appendages may be perturbed passively from a tripod gait on uneven terrain and return to a tripod gait on even terrain.
46. The vehicle of claim 44, wherein the frame comprises a front frame segment and a rear frame segment connected by a body flexion joint.
47. The vehicle of claim 46, wherein the body flexion joint may be actuated to allow the front frame segment to contact higher andor lower terrain, wherein the actuation is active, passive, or a combination of active and passive actuation.
48. The vehicle of claim 41, comprising two drive systems wherein the two drive systems are phased to employ a diagonal gait when the selected preload of the torsionally compliant devices has not been overcome.
49. The vehicle of claim 48, wherein each of the driving appendages includes a respective hub and a number of extending members, and wherein the diagonal gait is such that when an extending member of one driving appendage contacts the terrain, an extending member of the driving appendage located on the opposite drive system and on the opposite side of the vehicle contacts the terrain in generally the same manner.
50. The vehicle of claim 48, wherein the individual driving appendages may be perturbed passively from a diagonal gait on uneven terrain and return to a diagonal gait on even terrain.
51. A drive train, comprising:
a drive member;
a driven member;
a unidirectionally pretensioned compliant torsional member coupled between the drive and driven members to transmit powertorque from the drive member to the driven member and to allow a phase change between the drive member and the driven member in response to a forcetorque applied to the driven member;
a second drive member;
a second driven member;
a second unidirectionally pretensioned compliant torsional member coupled between the second drive member and the second driven member to transmit powertorque from the second drive member to the second driven member and to allow a phase change between the second drive member and the second driven member in response to a forcetorque applied to the second driven member; and
a pair of driving appendages being secured to an object in a manner to permit their rotation, wherein one of the appendages is coupled to the driven member and the other appendage is coupled to the second driven member,
wherein the pair of driving appendages cooperate to move the object over varying terrain and the compliant torsional members allow a relative phase change between the driving appendages in response to forces applied to the pair of driving appendages as they engage the terrain.