Method of reducing wafer stress by laser ablation of streets

• US 20020086137A1
• Filed: 12/28/2000
• Published: 07/04/2002
• Est. Priority Date: 12/28/2000
• Status: Abandoned Application

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Klinger-Park, Petra U., Dostie, Robert D., Brouillette, Donald W.
• Application Number:
  US09/751,018
• Publication Number:
  US 20020086137A1
• Time in Patent Office: Days
• US Class Current: 428/138
• CPC Class Codes: B23K 2101/40 Semiconductor devices
• CPC Class Codes: B23K 2103/172 wherein at least one of the layers is non-metallic
• CPC Class Codes: B23K 2103/30 Organic material
• CPC Class Codes: B23K 2103/50 Inorganic material, e.g. metals, not provided for in B23K2103/02 – B23K2103/26
• CPC Class Codes: B23K 26/364 for making a groove or trench, e.g. for scribing a break initiation groove
• CPC Class Codes: B23K 26/40 taking account of the properties of the material involved
• CPC Class Codes: H01L 21/3043 Making grooves, e.g. cutting
• CPC Class Codes: H01L 21/78 with subsequent division of the substrate into plural individual devices cutting to change the surface-physical characteristics or shape of semiconductor bodies H01L21/304
• CPC Class Codes: Y10T 428/24331 including nonapertured component

Abstract

A wafer is diced by non-abrasively forming a groove along at least one dicing channel without removing any materials as hard as diamond; optionally thinning the wafer by backside grinding and cutting through the wafer by sawing along the groove.

Claims

1. A method of dicing a wafer comprising:

a) providing a wafer comprising semiconductor material having a front surface and a back surface and having at least one dicing channel defined on said front surface;

b) non-abrasively forming a groove along said at least one dicing channel without removing any materials as hard as diamond; and

c) cutting through said wafer by sawing along said groove.

2. A method of dicing a wafer, according to claim 1, wherein said groove is formed by laser ablation.

3. A method of dicing a wafer, according to claim 1, further comprising the step of grinding said back surface of said wafer between steps (b) and (c).

4. A method of dicing a wafer, according to claim 1, wherein said wafer further comprises layers of insulation and metal and wherein said groove is formed through said layers.

5. A method of dicing a wafer, according to claim 1, and wherein said groove is formed partially through said semiconductor material.

6. A method of dicing a wafer, according to claim 1, wherein said wafer further comprises second dicing channels defined on said back surface and wherein the method further comprises the step of forming a groove along said second dicing channels after said grinding step and before said sawing step.

7. A method of dicing a wafer, according to claim 1, wherein said wafer further comprises a protective coating.

8. A semiconductor chip, fabricated according to the method of claim 1, comprising a top surface and at least one sidewall having a first portion proximal to said top surface and a portion distal to said top surface wherein said distal portion has striations from a saw.

9. A semiconductor chip, according to claim 1, wherein said proximal portion has marks indicating a laser scribe.

10. A semiconductor chip, according to claim 1, further comprising a passivation film on said top surface wherein said passivation film is sealed along said chip sidewall.