Patent EP0392399A2 successfully refreshed from Google Patents.
EP0392399A2
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Method and apparatus for wafer transfer
Assignee: Applied Materials Inc
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Filing: 1990-04-06
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Granted: —
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Expires: 2010-04-06
Abstract
Abstract A semiconductor wafer (14) transport system includes a blade (20) which incorporates electrostatic wafer clamping utilizing interleaved electrodes (42, 44) and particularly, a layer 46 of dialectric material overlaying said electrodes (42, 44) for maximizing the electrostatic clamping force generated between the wafer transport blade (20) and a semiconductor wafer (14) to prevent slippage of the wafer (14) off the blade (20) during blade accelerational movement.
Inventors
- 👤 Kenneth S. Collins
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 19:27
CPC Classifications
H; H10; H10P; H10P72/00; H10P72/30; H10P72/33; H10P72/3306; H10P72/70; H10P72/72; H10P72/76; H10P72/7602
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
123 words
A method for transferring wafers in a wafer fabrication or handling system utilizing an electrostatic wafer blade, comprising the steps of: placing a wafer to be transported on a top surface of the blade, said top surface having at least one pair of interleaved electrodes, alternating electrodes being connected in common electrically- said electrodes having a width and a spatial distance between said electrodes based on a correlated ratio defined by [electrode width/distance between electrodes] with a value ranging from 3/1 to 2/1; applying a voltage to said electrodes on said blade sufficient to induce a wafer-flattening electrostatic force between the wafer and the blade; and transporting the wafer on the blade to the intended destination and releasing it there from the blade.
Claim 2
Independent Claim
123 words
A method for transferring wafers in a wafer fabrication or handling system utilizing an electrostatic wafer blade, comprising the steps of: placing a wafer to be transported on a top surface of the blade, said top surface having at least one pair of interleaved electrodes, alternating electrodes being connected in common electrically- said electrodes having a width and a spatial distance between said electrodes based on a correlated ratio defined by [electrode width/distance between electrodes] with a value ranging from 3/1 to 2/1; applying a voltage to said electrodes on said blade sufficient to induce a wafer-flattening electrostatic force between the wafer and the blade; and transporting the wafer on the blade to the intended destination and releasing it there from the blade.
Claim 3
Dependent Claim
48 words
The method of claim 1 in which the movement of the blade holding the wafer is accelerated with a mechanical arm attached to the blade to effectuate controlled movement of the wafer in the system, whereby said clamping force holds the wafer onto the blade during accelerational movement.
Claim 4
Dependent Claim
86 words
The method of claim 1 or 2 comprising the further step of disposing a layer of dielectric material over at least one pair of interleaved electrodes of selected width on the top surface of a wafer transfer blade, said dielectric having a thickness ranging from approximately 0.05 µm (2 mils) to 0.38 µm (15 mils) for optimizing the force per unit of input voltage for a selected applied voltage in order to maximize the electrostatic clamping force of a semiconductor wafer to a wafer transfer blade.
Claim 5
Independent Claim
28 words
The method of one of the preceding claims wherein the selected electrode width is within the range of about 0.30 µm (12 mils) to 3.05 u.m (120 mils).
Claim 6
Independent Claim
28 words
The method of one of the preceding claims wherein the distance between electrodes is within the range of about 0.1 µm (4 mils) to 1.02 u.m (40 mils).
Claim 7
Independent Claim
122 words
An apparatus for wafer transfer comprising an electrostatic clamping blade (20), said blade (20) comprising: a base (32), at least one pair of interleaved electrodes (42,44) formed on said base (32), alternating electrodes (42,44) being connected in common electrically, a layer of dielectric material (46) over the interleaved electrodes (42,44) and the base (32), said dielectric material having a thickness sufficient to prevent dielectric breakdown when a clamping voltage is applied, and means for applying a voltage between said alternating electrodes (42,44) to generate an electrostatic clamping force between the blade (20) and a semiconductor wafer (14) positioned thereon, the ratio of electrode width to between electrode spacing being within the range of 3/1 to 2/1 to enhance the electrostatic clamping force.
Claim 8
Independent Claim
122 words
An apparatus for wafer transfer comprising an electrostatic clamping blade (20), said blade (20) comprising: a base (32), at least one pair of interleaved electrodes (42,44) formed on said base (32), alternating electrodes (42,44) being connected in common electrically, a layer of dielectric material (46) over the interleaved electrodes (42,44) and the base (32), said dielectric material having a thickness sufficient to prevent dielectric breakdown when a clamping voltage is applied, and means for applying a voltage between said alternating electrodes (42,44) to generate an electrostatic clamping force between the blade (20) and a semiconductor wafer (14) positioned thereon, the ratio of electrode width to between electrode spacing being within the range of 3/1 to 2/1 to enhance the electrostatic clamping force.
Claim 9
Dependent Claim
37 words
The apparatus of claim 6, wherein said layer (46) of dielectric is comprised of Al 2 O 3 and the thickness thereof is within the range of about 0.05 µm (2 mils) to 0.38 µm (15 mils).
Claim 10
Dependent Claim
22 words
The apparatus of claim 6 or 7 wherein said electrode thickness ranges from 0.3 µm (12 mils) to 3.05 µm (120 mils).
Claim 11
Independent Claim
27 words
The apparatus of one of claims 6 to 8, wherein said distance between the electrodes (42,44) ranges from 0.1 µm (4 mils) to 1.02 µm (40 mils).
References Cited (Backward Citations)
No citation records indexed.
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