Patent EP0134438A2 successfully refreshed from Google Patents.
EP0134438A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Vacuum and/or electrostatic pinchuck for holding semiconductor wafers or other flat electrical components and method for making the same
Assignee: International Business Machines Corp
•
Filing: 1984-06-20
•
Granted: —
•
Expires: 2004-06-20
Abstract
Abstract A method of forming a pinchuck is described using lithographic techniques to define and to etch a pattern of pins from an extremely flat surface. A block of suitable material is polished to form such an extremely flat surface. The desired pin pattern (preferably along with a vacuum sealing ring surrounding the pins) is defined with a mask, which is then used to etch the flat surface so as to form an array of pins (and optional sealing ring). Since the pins (and the optional vacuum sealing ring) are formed from a surface which is already flat, it is not necessary to polish the pins after they are formed. The top surfaces of the pins (and the top surface of the optional vacuum sealing ring) already lie within a common plane. Since lithographic techniques are used, the pin head dimensions, the number of pins, the arrangement of pins, and the density of pins all may be freely chosen without affecting the fabrication cost. The drawings shows the completed pinchuck in use as a vacuum pinchuck supporting a silicon wafer 36. The pinchuck comprises a block of silicon having two holes 14,15 in it through which vacuum suction and an electrical connection 38 can be made to a wafer 36 mounted on the chuck. The chuck comprises the pins 30 and the annual sealing ring or flange 32. The surface layer 34 of the block is oxydised while the base is not to allow electrical contact to be made therewith.
Inventors
- 👤 Vincent Dimilia
- 👤 Juan Ramon Maldonado
- 👤 James Louis Speidell
- 👤 John Michael Warlaumont
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 20:14
CPC Classifications
H; H10; H10P; H10P72/00; H10P72/70; H10P72/76; H10P72/7604; H10P72/7614; G; G03; G03F; G03F7/00; G03F7/70; G03F7/70691; G03F7/707; Y; Y10; Y10S; Y10S269/00; Y10S269/902
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
51 words
A pinchuck of the type wherein pins extend from and are supported by a base, said pins having flat top surfaces all lying in a common plane, characterised in that said base and pins are of unitary construction formed by etching from a single block of material having a flat surface.
Claim 2
Dependent Claim
51 words
A pinchuck of the type wherein pins extend from and are supported by a base, said pins having flat top surfaces all lying in a common plane, characterised in that said base and pins are of unitary construction formed by etching from a single block of material having a flat surface.
Claim 3
Dependent Claim
15 words
A pinchuck as claimed in Claim 1, wherein said pins are coated with dielectric material.
Claim 4
Dependent Claim
55 words
A pinchuck as claimed in Claim 1 or 2, wherein said unitary construction includes a ring also formed by etching from said single block of material, said ring surrounding said pins and extending from said base to a flat top surface thereof, said flat top surface of said ring also lying in said common plane.
Claim 5
Dependent Claim
19 words
A pinchuck as claimed in Claim 1, 2 or 3, wherein the material of said block is semiconductor material.
Claim 6
Dependent Claim
16 words
A pinchuck as claimed in Claim 4, wherein the material of said block is doped silicon.
Claim 7
Independent Claim
83 words
A method of forming a pinchuck, characterised by comprising forming a flat surface on a block of etchable material; and etching said flat surface through a lithographic mask which defines an array of pins, whereby the resulting etched pins extend from and are supported by a resulting base, each etched pin having a flat top surface corresponding with said flat surface of said block of etchable material, all of said flat top surfaces of said pins thereby lying in a common flat plane.
Claim 8
Independent Claim
83 words
A method of forming a pinchuck, characterised by comprising forming a flat surface on a block of etchable material; and etching said flat surface through a lithographic mask which defines an array of pins, whereby the resulting etched pins extend from and are supported by a resulting base, each etched pin having a flat top surface corresponding with said flat surface of said block of etchable material, all of said flat top surfaces of said pins thereby lying in a common flat plane.
Claim 9
Dependent Claim
44 words
A method as claimed in Claim 6, wherein said lithographic mask also defines a ring surrounding said pins whereby the resulting ring also extends from said base and has a flat top surface corresponding with said flat surface of said block of etchable material.
Claim 10
Dependent Claim
26 words
A method as claimed in Claim 6 or 7, wherein said etchable material is monocrystalline semiconductor material and said etching is done with an anisotropic etchant.
Claim 11
Dependent Claim
31 words
A method as claimed in Claim 6, 7 or 8, and further comprising the step of covering the surface of said pins with a dielectric material, thereby forming an electrostatic pinchuck.
Claim 12
Dependent Claim
31 words
A method as claimed in Claim 9 wherein said dielectric material is a native oxide of the material comprising said block and is formed by oxidizing the surface of said pins.
Claim 13
Dependent Claim
104 words
A pinchuck for holding an electrically conductive object having a nominally flat surface, comprising: an electrically conductive base; an array of electrically conductive pins in electrical contact with said base and extending substantially perpendicularly from said base, said pins each having a flat top surface lying in a common flat plane; a dielectric coating covering at least the top surface of said pins; and means for applying a voltage potential between said base and an electrically conductive object lying in contact with the dielectric coating on the top surface of said pins, whereby said object may be held against said pinchuck by electrostatic force.
Claim 14
Dependent Claim
104 words
A pinchuck for holding an electrically conductive object having a nominally flat surface, comprising: an electrically conductive base; an array of electrically conductive pins in electrical contact with said base and extending substantially perpendicularly from said base, said pins each having a flat top surface lying in a common flat plane; a dielectric coating covering at least the top surface of said pins; and means for applying a voltage potential between said base and an electrically conductive object lying in contact with the dielectric coating on the top surface of said pins, whereby said object may be held against said pinchuck by electrostatic force.
Claim 15
Dependent Claim
29 words
A pinchuck as claimed in any one of claims 1 to 5 or claim 11, wherein the pin density is on the order of 25 pins per square centimeter.
Claim 16
Dependent Claim
34 words
A pinchuck as claimed in any one of claims 1 to 5, 11 or 12, wherein the flat top surface area of each of said pins is on the order of one square millimeter.
Claim 17
Dependent Claim
31 words
A pinchuck as claimed in any one of claims 1 to 5, 11, 12 or 13, wherein the distance between adjacent pin top surfaces is on the order of one millimeter.
Claim 18
Dependent Claim
109 words
A pinchuck as claimed in claim 11, 12, 13 or 14, further comprising: an electrically conductive vacuum sealing ring sealed to and in electrical contact with said base, said ring surrounding said pins and extending from said base to a flat top surface thereof, said flat top surface of said ring also lying in said common plane and being covered with said dielectric coating; and a hole through said base for withdrawing air from the region between said pins to form a relative vacuum within said region, whereby an object covering said flat top surface of said sealing ring may be held against said pinchuck by vacuum induced forces.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.