Asymmetrical wafer configurations and method for creating the same

• US 8,389,099 B1
• Filed: 06/01/2007
• Issued: 03/05/2013
• Est. Priority Date: 06/01/2007
• Status: Expired due to Fees

• Current Assignee: Rubicon Technology, Inc.
• Original Assignee: Rubicon Technology, Inc.
• Inventors: Matthews, Michael W, Phatak, Sunil B.
• Primary Examiner(s): O'HERN, BRENT T
• Application Number:
  US11/756,899
• Time in Patent Office: 2,104 Days
• Field of Search: 428/66.7, 428/64.1, 257/797, 148/33.2
• US Class Current: 428/66.7
• CPC Class Codes: H01L 21/02013 Grinding, lapping
• CPC Class Codes: H01L 21/02021 Edge treatment, chamfering
• CPC Class Codes: H01L 21/02024 Mirror polishing
• CPC Class Codes: H01L 21/02035 Shaping
• CPC Class Codes: H01L 2223/54426 for alignment
• CPC Class Codes: H01L 2223/54493 Peripheral marks on wafers, e.g. orientation flats, notches, lot number
• CPC Class Codes: H01L 23/544 Marks applied to semiconductor devices or parts, e.g. registration marks, alignment structures, wafer maps test patterns for characterising or monitoring manufacturing processes H01L22/00
• CPC Class Codes: H01L 29/0657 characterised by the shape of the body
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: Y10T 428/21 Circular sheet or circular blank
• CPC Class Codes: Y10T 428/219 Edge structure

Abstract

The present invention consists of a method for imparting asymmetry to a truncated annular wafer by either rounding one corner of the orientation flat, or rounding one corner of a notch. This novel method of rounding corners impart a visual and/or tactile asymmetry which can be utilized by a person in order to differentiate between the two different sides of the wafer. This inventive wafer design and method for making an asymmetric wafer is especially useful in the field of semiconductor technology and may be used on sapphire crystal wafers or any other class of wafer.

Claims

1. A substantially rigid, thin annular crystalline wafer, comprising:

a top surface, a bottom surface, and an edge surface, where the edge surface is provided with at least one truncated flat portion, and the flat portion is further provided with at least two opposing shaped corners wherein one of the at least two opposing shaped corners has a shape that differs from a shape of another of the at least two opposing shaped corners, and wherein at least one of the two opposing corners is rounded.

2. The substantially annular wafer in claim 1, wherein said substantially annular wafer further comprises a secondary truncated flat portion.

3. A substantially rigid, thin annular wafer, comprising:

a top surface, a bottom surface, and an edge surface, where the edge surface is provided with at least one truncated flat portion, and the flat portion is further provided with at least two opposing shaped corners wherein one of the at least two opposing shaped corners has a shape that differs from a shape of another of the at least two opposing shaped corners, wherein the at least two opposing shaped corners have been rounded to differing radii and are visually asymmetric with respect to one another.

4. A substantially rigid, thin annular wafer, comprising:

a top surface, a bottom surface, and an edge surface, where the edge surface is provided with at least one truncated flat portion, and the flat portion is further provided with at least two opposing shaped corners wherein one of the at least two opposing shaped corners has a shape that differs from a shape of another of the at least two opposing shaped corners, wherein said substantially annular wafer further comprises a secondary truncated flat portion, wherein the secondary truncated flat contains at least one rounded corner creating a visual asymmetry in the wafer.

5. A substantially rigid, thin circular wafer, comprising:

a top surface, a bottom surface, and an edge surface, where the edge surface is provided with at least one portion having a notch, and said notch is further provided with at least two opposing shaped corners wherein at least one corner has a shape which differs from the other corner in the notch.

6. The substantially circular wafer in claim 5, wherein said notch consists of a configuration which is selected from a group of one or more of the following shapes:

substantially angular, trapezoidal, square, triangular, semispherical, elliptical, circular or oval.

7. The substantially circular wafer in claim 6, wherein both corners of the notch are rounded to differing radii thereby creating visual asymmetry in the wafer.

8. The substantially circular wafer in claim 5, wherein said substantially circular wafer further comprises a secondary notch.

9. The substantially circular wafer in claim 8, wherein said secondary notch has at least one rounded corner.