1. A driveshaft system comprising:
a driveline of a motor vehicle comprising a tubular driveshaft; and
at least one attenuator positioned within the tubular driveshaft, the attenuator comprising a dampening material disposed about a perimeter of a rigid carrier corresponding to an interior surface of the tubular driveshaft, wherein the rigid carrier provides a balanced distribution of the dampening material about the interior surface of the tubular driveshaft.
2. The driveshaft system of claim 1 wherein the at least one attenuator is positioned at least one frequency node within the tubular driveshaft.
3. The driveshaft system of claim 1 wherein the attenuator substantially reduces acoustical wave propagation in the driveline of the motor vehicle.
4. The driveshaft system of claim 1 wherein the rigid carrier comprises a cylindrical configuration.
5. The driveshaft system of claim 4 wherein the cylindrical configuration comprises a solid rim about a substantially hollow center portion, wherein an outer surface of the solid rim is the perimeter on which the dampening material is disposed.
6. The driveshaft system of claim 5 wherein the rigid carrier comprises cross bracing across the hollow central portion of the rigid carrier.
7. The driveshaft system of claim 1 wherein the tubular driveshaft comprises aluminum.
8. The driveshaft system of claim 8 wherein the tubular driveshaft comprises a driveshaft diameter to driveshaft wall thickness ratio on the order of 18 or greater.
9. The driveshaft system of claim 1 wherein the at least one attenuator is positioned at a center of a length of the tubular driveshaft.
10. The driveshaft system of claim 1 wherein the at least one attenuator comprises a first attenuator positioned at \u2153 a length of said tubular driveshaft and a second attenuator positioned at \u2154 said length of the tubular driveshaft.
11. The driveshaft system of claim 1 wherein the at least one attenuator is positioned at frequency nodes within the tubular driveshaft and comprises a dampening material for dampening a first frequency range of sound waves or vibrations and the rigid carrier substantially reduces a second frequency range of sound waves or vibrations.
12. The system of claim 11 wherein said first frequency range of sound waves or vibrations is greater than the second frequency of sound waves or vibrations.
13. The system of claim 11 wherein a portion of said first frequency range overlaps with the second frequency range.
14. The system of claim 11 wherein the first frequency range comprises sound waves or vibrations is generated by differentials, transmissions, transaxles, half-shafts, universal joints, and velocity joints in the driveline.
15. The system of claim 11 wherein the second frequency range comprises sound waves or vibrations generated by dimensional changes in the tubular driveshaft.
16. The system of claim 11 wherein the rigid carrier further comprises retaining lips at opposing ends of the perimeter of the rigid carrier, wherein the retaining lips contain the dampening material in balanced engagement with the interior surface of the tubular driveshaft.
17. The system of claim 6 wherein the cross bracing segments the air space along a diameter of the tubular driveshaft, wherein the segmented air space within the tubular driveshaft increases noise and vibration frequencies produced by the tubular driveshaft.
18. A driveshaft comprising:
a tube having an interior surface; and
at least one least attenuator positioned at frequency nodes within the tube, wherein each of the at least one attenuator comprises a rigid carrier engaged to the interior surface of the tube by a dampening material, the rigid carrier having a geometry that contains the dampening material in a balanced engagement to the interior surface of the tube and substantially increases dimensional rigidity in a diameter of the tube.
19. The driveshaft of claim 18 further comprising end caps on opposing ends of said tube, wherein each of the end caps provide a connection to driveline components.
20. A method of manufacturing a driveshaft comprising:
providing a tubular driveshaft having an interior surface;
providing a rigid carrier housing an expandable material, the rigid carrier having an exterior geometry corresponding to the interior surface of the tubular driveshaft, wherein the expandable material is disposed upon the exterior geometry of the rigid carrier;
inserting the rigid carrier within the tubular driveshaft; and
activating the expandable material into engagement with the interior surface of the tubular driveshaft, wherein the rigid carrier confines the expandable material upon activation in a balanced distribution about the interior surface of the tubular driveshaft.
21. The method of claim 20 wherein the rigid carrier and the expandable material substantially reduces acoustical wave propagation.
22. The method of claim 21 wherein the geometry of the rigid carrier comprises a hollow cylindrical configuration.
23. The method of claim 20 wherein the rigid carrier comprises cross bracing along a central portion of the rigid carrier.
24. The method of claim 20 wherein the expandable material bonds to the interior surface of the tubular driveshaft.
25. The method of claim 20 wherein the rigid carrier further comprises retaining lips at opposing ends of the rigid carrier, wherein the retaining lips contain the expandable material in balanced engagement with the interior surface of the tubular driveshaft.
26. A method of manufacturing a driveshaft:
providing a tubular driveshaft having an interior surface;
inserting at least one attenuator within said tubular driveshaft at least one frequency node, wherein the attenuator comprises a dampening material disposed around a perimeter of a rigid carrier; and
activating the dampening material into engagement with said interior surface of the tubular driveshaft, wherein the rigid carrier contains the dampening material in a balanced distribution about the interior surface of the tubular driveshaft and substantially reduces dimensional changes in a diameter of the tubular driveshaft.
27. The method of claim 26 wherein the at least one attenuator comprises a dampening material for dampening a first frequency range of sound waves or vibrations and the rigid carrier substantially reduces a second frequency range of sound waves or vibrations.
28. The system of claim 27 wherein the first frequency range comprises sound waves or vibrations is generated by differentials, transmissions, transaxles, half-shafts, universal joints, and velocity.joints in the driveline.
29. The system of claim 27 wherein the second frequency range comprises sound waves or vibrations generated by dimensional changes in the tubular driveshaft.
30. The system of claim 6 wherein the rigid carrier further comprises cross bracing that segments the air space along a diameter of the tubular driveshaft, wherein the segmented air space within the tubular driveshaft increases noise and vibration frequencies produced by the tubular driveshaft.
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 method for fabricating a high voltage semiconductor device, the method comprising:
providing a substrate having a surface region;
forming a well region within the substrate;
forming a double diffused drain region within the well region;
forming a gate dielectric layer overlying the surface region;
forming a gate polysilicon layer overlying the gate dielectric layer;
forming a mask layer overlying the gate polysilicon layer;
patterning the gate polysilicon layer to form a gate electrode having a first predetermined width and a predetermined thickness, the gate electrode having a first side and a second side formed between the first predetermined width, the gate electrode being coupled to the double diffused drain region within the well region, the first side having a lower corner overlying the gate dielectric layer and an upper corner underlying the mask layer, the second side having a lower corner overlying the gate dielectric layer and an upper corner underlying the mask layer;
causing an oxidation of the gate electrode such that the lower corner on the first side and the lower corner on the second side convert from polysilicon material into silicon dioxide while the upper corner on the first side and the upper corner on the second side are substantially free from oxidation; and
continuing to convert the lower corner of the first side and the lower corner of the second side to reduce the first predetermined with of the gate electrode comprising polysilicon material to a second predetermined width comprising polysilicon material to increase a breakdown voltage of the high voltage semiconductor device to greater than 20 volts.
2. The method of claim 1 wherein the gate electrode comprises a doped polysilicon material.
3. The method of claim 1 wherein the second predetermined width is less than the first predetermined width.
4. The method of claim 1 wherein the upper corner on the first side and the upper corner on the second side are substantially protected by the overlying mask layer from oxygen bearing species.
5. The method of claim 1 wherein the oxidation is provided by an oxygen bearing species.
6. The method of claim 1 wherein the oxidation is maintained at a temperature ranging from about 600 Degrees Celsius to about 750 Degrees Celsius.
7. The method of claim 1 wherein the mask layer is a silicon nitride layer.
8. The method of claim 1 wherein the mask layer is a tungsten silicide layer.
9. The method of claim 1 wherein the lower corner of the first side and the lower corner of the second side are substantially oxide and insulating in characteristic.