Semiconductor wafer dicing techniques
First Claim
1. A method for separating a wafer of III-V compound semiconductor material into dice wherein the wafer has at least some repetitious device geometries embedded into a first of two major surfaces corresponding to dice areas, the method comprising the steps of:
- defining a first patterned mask on the first major surface, the first patterned mask having open areas in the form of lanes generally intersecting conforming to regions between dice geometries and closed areas conforming to the regions occupied by the dice areas;
etching the lanes to a depth below the plane of the first major surface;
removing the first patterned mask from the first major surface;
mounting the wafer on the first major surface so that the second of the two major surfaces is exposed;
defining a metallized pattern on the second major surface aligned with the dice areas on the first major surface;
removing semiconductor material from the lanes on the second major surface to form dice from the wafer; and
etching exposed semiconductor material remaining in the lanes to remove semiconductor material immediately adjacent to the previously removed material.
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Accused Products
Abstract
A dice separation technique involves producing a depressed street pattern (14) on the front device processing major surface of a wafer (11) before thinning the wafer down to a desired thickness. After mounting the wafer (11) on a suitable carrier, it is thinned down and selectively metallized to from backside contacts. Semiconductor material is removed from the central regions of the streets (14). Exposed material damaged by the material removal is also removed to eliminate micro-cracking while producing dice (12 and 13) having straight and smooth orthogonal edges. The present technique is particularly suitable for working with brittle compound semiconductor material between die areas having FETs or MMICs embedded therein.
99 Citations
12 Claims
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1. A method for separating a wafer of III-V compound semiconductor material into dice wherein the wafer has at least some repetitious device geometries embedded into a first of two major surfaces corresponding to dice areas, the method comprising the steps of:
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defining a first patterned mask on the first major surface, the first patterned mask having open areas in the form of lanes generally intersecting conforming to regions between dice geometries and closed areas conforming to the regions occupied by the dice areas; etching the lanes to a depth below the plane of the first major surface; removing the first patterned mask from the first major surface; mounting the wafer on the first major surface so that the second of the two major surfaces is exposed; defining a metallized pattern on the second major surface aligned with the dice areas on the first major surface; removing semiconductor material from the lanes on the second major surface to form dice from the wafer; and etching exposed semiconductor material remaining in the lanes to remove semiconductor material immediately adjacent to the previously removed material. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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Specification