What is claimed is:
1. A device for forming an ion sheath in a plasma to deposit a film on a non-conducting substrate, said device comprising:
a tubular reaction chamber having an outer surface; and
a first electrode having a first width, said first electrode wound helically to provide a plurality of first wraps around said outer surface of said tubular reaction chamber; and
a second electrode having a second width that is larger than said first width, said second electrode wound helically to provide a plurality of second wraps alternating with said first wraps around said outer surface of said tubular reaction chamber, said ion sheath in said plasma forming to a thickness extending into said tubular reaction chamber at least to the longitudinal axis thereof, for ion bombardment of the non-conducting substrate, to deposit said film thereon when said first electrode has a connection to a source of radio-frequency power and said second electrode provides a path to ground.
2. The device of claim 1, wherein said tubular reaction chamber is a glass tubular reaction chamber.
3. The device of claim 1, wherein said tubular reaction chamber has a radius less than said thickness of said ion sheath in said plasma.
4. The device of claim 3, wherein said radius of said tubular reaction chamber is less than about 25.0 mm.
5. The device of claim 3, wherein said radius of said tubular reaction chamber is less than about 12.0 mm.
6. The device of claim 1, wherein said non-conducting substrate is a filamentary substrate.
7. The device of claim 6, wherein said filamentary substrate is a glass optical fiber.
8. A process for depositing a layer of material on an optical fiber comprising the steps of:
providing a supply of an optical fiber;
threading said optical fiber through a processing column to an accumulator for a treated optical fiber, said processing column including an entry to receive said optical fiber and an exit for passage of said treated optical fiber to said accumulator, said processing column further including a reaction chamber between said entry and said exit;
evacuating said processing column to provide a reduced pressure inside said reaction chamber comprising a tube wrapped helically with a first electrode and a second electrode;
maintaining a flow of a process gas at low pressure through said reaction chamber; and
applying power at a radiofrequency to said first electrode and connecting said second electrode to ground to generate an ion sheath in a plasma, said ion sheath having a thickness for ion bombardment during movement of said stripped optical fiber to deposit said layer of material thereon to provide said treated optical fiber for collection by said accumulator.
9. The process of claim 8, wherein said reaction chamber is a tubular reaction chamber.
10. The process of claim 9, wherein said tubular reaction chamber is a glass tubular reaction chamber.
11. The process of claim 9, wherein said tubular reaction chamber has a radius less than said thickness of said ion sheath in said plasma.
12. The process of claim 11, wherein said radius of said tubular reaction chamber is less than about 25.0 mm.
13. The process of claim 8, wherein said reduced pressure is below about 130.0 Pa (1.0 Torr).
14. The process of claim 8, wherein said reduced pressure is in a range from about 26.0 Pa (0.2 torr) and about 39.0 Pa (0.3 torr).
15. The process of claim 8, wherein said process gas comprises tetramethyl silane and oxygen.
16. The process of claim 15, wherein said process gas comprises a ratio of tetramethylsilane to oxygen from about 0.1 to about 5.0.
17. The process of claim 15, wherein said process gas comprises a ratio of tetramethylsilane to oxygen from about 0.5 to about 2.0.
18. The process of claim 8, wherein said radiofrequency is about 13.56 MHz.
19. The process of claim 8, wherein said power of said radiofrequency is about 60 W.
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 of determining an initial state of a reference cell in a fabricated memory array, the method comprising:
performing a first read operation of the reference cell by comparing current through the reference cell with the average current passing through a pair of data cells, and storing the result of the first read operation;
inverting the value of one of the pair of the data cells;
performing a second read operation of the reference cell, and storing the result of the second read operation;
inverting the value of the other of the pair of the data cells;
performing a third read operation of the reference cell, and storing the result of the third read operation; and
performing a majority compare operation of the results of the first, second and third operations;
wherein the result of the majority compare operation is the initial state of the reference cell.
2. The method of claim 1, wherein the memory array comprises a toggle switched MRAM device.
3. The method of claim 2, further comprising switching a column decoder so as to couple the reference cell to a data input of a first sense amplifier and couple the average current passing through the pair of data cells to a reference input of the first sense amplifier.
4. The method of claim 3, further comprising using the average current passing through the pair of data cells to simultaneously determine an initial state of another reference cell associated with a second sense amplifier adjacent to the first sense amplifier.
5. The method of claim 4, wherein the reference input of the first sense amplifier is shorted to a reference input of the second sense amplifier.
6. A method of initializing a reference cell in a toggle switched MRAM device, the method comprising:
performing a first read operation of the reference cell by comparing current through the reference cell with the average current passing through a pair of data cells, and storing the result of the first read operation;
inverting the value of one of the pair of the data cells;
performing a second read operation of the reference cell, and storing the result of the second read operation;
inverting the value of the other of the pair of the data cells;
performing a third read operation of the reference cell, and storing the result of the third read operation;
performing a majority compare operation of the results of the first, second and third operations, wherein the result of the majority compare operation is the initial state of the reference cell and
toggling the reference cell in the event the initial state of the reference cell does not match a desired state of the reference cell.
7. The method of claim 6, further comprising switching a column decoder so as to couple the reference cell to a data input of a sense amplifier and couple the average current passing through the pair of data cells to a reference input of the sense amplifier.
8. The method of claim 7, further comprising using the average current passing through the pair of data cells to simultaneously determine an initial state of another reference cell associated with a second sense amplifier adjacent to the first sense amplifier.
9. The method of claim 8, wherein the reference input of the first sense amplifier is shorted to a reference input of the second sense amplifier.
10. An apparatus for initializing a reference cell in a toggle switched MRAM device, the method comprising:
a first sense amplifier configured for performing a first read operation of the reference cell by comparing current through the reference cell with the average current passing through a pair of data cells;
a first latch for storing the result of the first read operation;
a second latch for storing the result of a second read operation by the first sense amplifier, wherein the second read operation is performed following the first read operation and the inversion of the value of one of the pair of the data cells;
a third latch for storing the result of a third read operation by the first sense amplifier, wherein the third read operation is performed following the second read operation and the inversion of the value of the other of the pair of the data cells;
and a majority compare device configured to compare the results of the first, second and third operations respectively stored in the first, second and third latches, wherein an output of the majority compare operation is the initial state of the reference cell.
11. The apparatus of claim 10, further comprising logic for toggling the reference cell in the event the initial state of the cell does not match a desired state of the reference cell.
12. The apparatus of claim 11, further comprising a column decoder configured to selectively couple the reference cell to a data input of the first sense amplifier and couple the average current passing through the pair of data cells to a reference input of the first sense amplifier.
13. The apparatus of claim 11, further comprising a second sense amplifier configured to simultaneously determine an initial state of another reference cell using the average current passing through the pair of data cells.
14. The apparatus of claim 13, wherein the reference input of the first sense amplifier is shorted to a reference input of the second sense amplifier.