What is claimed is:
1. A method for releasing a microstructure for fabricating a device of a micro electro mechanical system (MEMS), comprising the steps of;
supplying alcohol vapor bubbled with anhydrous HF;
maintaining a temperature of the supplying device and a moving path of the anhydrous HF and the alcohol to be higher than a boiling point of the alcohol;
performing a vapor etching by controlling a temperature and a pressure to be within the vapor region of a phase equilibrium diagram of water; and
removing silicon oxide of a sacrificial layer on a lower portion of the microstructure.
2. The method of claim 1, wherein the vapor etching is performed under a pressure ranged to be 25-75 torr.
3. The method of claim 1, wherein the vapor etching is performed under a temperature ranged to be 25-80 C.
4. The method of claim 1, wherein a step of performing a wet etching of a part of the silicon oxide precedes the step of performing the vapor etching.
5. The method of claim 1, wherein the silicon oxide of a sacrificial layer is any one component selected from the group consisting of TEOS, LTO, PSG, BPSG and a thermal silicon oxide.
6. The method of claim 1, wherein the alcohol is any one component selected from the group consisting of methanol, isopropyl alcohol aid ethanol.
7. The method of claim 1, wherein the MEMS device has a laminated layer structure or a monocrystal silicon structure.
8. A method for removing silicon oxide of a sacrificial layer for a microstructure in a MEMS device, characterized by removing the silicon oxide of a sacrificial layer with a vapor etching using anhydrous HF and alcohol by controlling a temperature and a pressure inside of an etching chamber to be within the region of a vapor of a phase equilibrium diagram of water.
9. The method of claim 8, wherein the pressure inside of the etching chamber is ranged to be 25-75 torr.
10. The method of claim 8, wherein the temperature inside of the etching chamber is ranged to be 25-80 C.
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 buoy having an exterior, said buoy comprising:
a fixed buoyancy portion formed with an enclosure;
a variable buoyancy portion inserted into said enclosure so that said fixed buoyancy portion surrounds said variable buoyancy portion;
said fixed buoyancy portion being formed with at least one opening to establish a path of fluid communication between the exterior of said buoy and said variable buoyancy portion;
an underwater docking station; and,
a tether connecting said fixed buoyancy portion to said underwater docking station.
2. The buoy of claim 1, wherein said fixed buoyancy portion is formed with a cavity, and further comprising a pressure vessel body located within said cavity.
3. The buoy of claim 1 wherein said variable buoyancy portion has a variable volume, a maximum volume and a minimum volume, and further wherein said minimum volume occurs when said fixed buoy is stowed at said docking station.
4. The buoy of claim 1 wherein said variable buoyancy portion is a compressible bladder.
5. The buoy of claim 1 wherein said variable buoyancy portion is made of compressible foam.
6. The buoy of claim 1 wherein said fixed buoyancy portion has a spar buoy configuration.
7. The buoy of claim 1 wherein said fixed buoyancy portion has a marker buoy configuration.
8. A buoy, comprising:
a variable buoyancy portion;
a fixed buoyancy portion surrounding said variable buoyancy portion;
said fixed buoyancy portion being formed with at least one opening to allow for water to pass through said fixed buoyancy portion and contact said variable buoyancy portion;
an underwater docking station; and,
a tether connecting said fixed buoyancy portion to said underwater docking station.
9. The buoy of claim 8, wherein said fixed buoyancy portion is formed with a cavity, and further comprising a pressure vessel body located with said cavity.
10. The buoy of claim 8, wherein said buoy is formed with a cavity, and further comprising a pressure vessel body located within said cavity.
11. The buoy of claim 8 wherein said variable buoyancy portion has a variable volume, a maximum volume and a minimum volume, and further wherein said minimum volume occurs when said buoy is stowed at said docking station.
12. The buoy of claim 8 wherein said variable buoyancy portion is a compressible bladder.
13. The buoy of claim 8 wherein said variable buoyancy portion is made of compressible foam.
14. The buoy of claim 8 wherein said fixed buoyancy portion has a spar buoy configuration.
15. A method for deploying a buoy, comprising the steps of:
A) providing a variable buoyancy portion;
B) surrounding said variable buoyancy portion with a fixed buoyancy portion; and,
C) forming with at least one opening in said fixed buoyancy portion to allow for water to pass through said fixed buoyancy portion and contact said variable buoyancy portion
D) stowing said buoy underwater at a docking station, said buoy having a minimum buoyancy Bmin, when said buoy is stowed; and,
E) releasing said buoy from said docking station, said Bmin being sufficient for said buoy to rise upon accomplished of said releasing step.
16. The method of claim 15, wherein said step A) is accomplished using a variable buoyancy portion selected from the group consisting of a compressible bladder and compressible foam.
17. The method of claim 15, wherein said step B) is accomplished using a fixed buoyancy portion having a configuration selected from the group consisting of a spar buoy and a marker buoy.