Methods and systems for imaging and cutting semiconductor wafers and other semiconductor workpieces

Patent metadata

Field	Value
Publication number	US-9579825-B2
Application number	US-201314093682-A
Country	US
Kind code	B2
Filing date	Dec 2, 2013
Priority date	Jun 19, 2007
Publication date	Feb 28, 2017
Grant date	Feb 28, 2017

Abstract

Methods and systems for imaging and cutting semiconductor wafers and other microelectronic device substrates are disclosed herein. In one embodiment, a system for singulating microelectronic devices from a substrate includes an X-ray imaging system having an X-ray source spaced apart from an X-ray detector. The X-ray source can emit a beam of X-rays through the substrate and onto the X-ray detector, and X-ray detector can generate an X-ray image of at least a portion of the substrate. A method in accordance with another embodiment includes detecting spacing information for irregularly spaced dies of a semiconductor workpiece. The method can further include automatically controlling a process for singulating the dies of the semiconductor workpiece, based at least in part on the spacing information. For example, individual dies can be singulated from a workpiece via non-straight line cuts and/or multiple cutter passes.

First claim

We claim:

1. A system for singulating microelectronic devices from a microelectronic substrate, the microelectronic substrate having an infrared inhibiting layer covering at least a portion of one side of the microelectronic substrate, the system comprising:
an X-ray source configured to emit X-rays;
an X-ray detector spaced apart from the X-ray source, wherein the X-ray detector is configured to receive at least a portion of the X-rays from the X-ray source when the infrared inhibiting layer of the microelectronic substrate is positioned between the X-ray source and the X-ray detector; and
a cutting device configured to respond to operating signals based at least in part on X-ray image information received from the X-ray detector, the X-ray image information corresponding to a location of an irregularly spaced die, the operating signals controlling a path of the cutting device as the cutting device cuts around the irregularly spaced die to singulate the irregularly spaced die from the microelectronic substrate.

2. The system of claim 1 wherein the cutting device moves independently of the X-ray source.

3. The system of claim 1 , further comprising a wafer holder configured to support the microelectronic device substrate, wherein the X-ray detector is coupled to the wafer holder.

4. The system of claim 1 , further comprising a wafer holder configured to support the microelectronic device substrate, wherein the X-ray detector is integrated into the wafer holder.

5. The system of claim 1 wherein the microelectronic substrate is a semiconductor wafer having at least one alignment feature, and wherein the cutting system further comprises a computer operably coupled to the X-ray detector and the cutting device, wherein the X-ray detector provides an X-ray image of the alignment feature to the computer, and the computer provides the operating signals to the cutting device based at least in part on the X-ray image from the X-ray detector.

6. The system of claim 1 wherein the X-ray detector includes a detector screen, and wherein the cutting system further comprises:
an X-ray image intensifier operably coupled to the detector screen; and
computer operably coupled to the X-ray image intensifier and the cutting device, wherein the X-ray image intensifier provides an X-ray image of an alignment feature to the computer, the alignment feature at least partially identifying the location of the irregularly spaced die, and wherein the computer provides the operating signals to the cutting device based at least in part on the X-ray image from the X-ray image intensifier.

7. A system for cutting a semiconductor wafer into a plurality of dies, the semiconductor wafer having a metal layer covering at least a portion of one side of the semiconductor wafer, the system comprising:
an fluoroscopic X-ray imaging system including:
an X-ray source configured to emit X-rays through at least a portion of the metal layer of the semiconductor wafer proximate to one or more features associated with an irregularly spaced die;
an X-ray detector screen positioned to receive at least a portion of the X-rays passing through the metal layer, wherein the X-ray detector screen is configured to generate an X-ray image of the one or more features; and
a processor operably coupled to the X-ray detector screen, wherein the processor is configured to receive the X-ray image of the one or more features from the X-ray detector screen and determine positional information related to the irregularly spaced die based at least in part on the X-ray image; and

a dicing machine operably coupled to the processor, wherein the dicing machine is configured to receive operating instructions from the processor based at least in part on the positional information related to the irregularly spaced die.

8. The system of claim 7 wherein the dicing machine includes a cutting device, and wherein the operating instructions cause the cutting device to cut the semiconductor wafer into a plurality of dies.

9. The system of claim 7 wherein the dicing machine includes a laser cutting device.

10. The system of claim 7 wherein the dicing machine includes a water jet cutting device.

11. The system of claim 7 wherein the X-ray source is coupled to the dicing machine, and wherein the system further includes:
a wafer holder configured to support the semiconductor wafer during X-ray imaging and cutting, wherein the X-ray detector is coupled to the wafer holder.

12. A system for cutting a semiconductor wafer, the system comprising:
means for directing X-rays through a layer of obscuring material on the semiconductor wafer, wherein the layer of obscuring material prevents the detection of at least one wafer alignment feature by visual or infrared means;
means for detecting at least a portion of the X-rays passing through the layer of obscuring material; and
means for cutting the semiconductor wafer; and
a controller having instructions directing the means for cutting to cut the semiconductor wafer with kerfs of different widths based at least in part on information received from the means for detecting.

13. The system of claim 12 , further comprising movable means for positioning the semiconductor wafer between an X-ray source and an X-ray detector.

14. The system of claim 12 wherein the means for detecting at least a portion of the X-rays passing through the layer of obscuring material include means for generating an X-ray image of the at least one wafer alignment feature.

15. The system of claim 12 wherein the means for detecting at least a portion of the X-rays passing through the layer of obscuring material include means for generating an X-ray image of the at least one wafer alignment feature, and wherein the system further comprises means for determining the location of the at least one alignment feature based at least in part on the X-ray image, wherein the means for cutting the semiconductor wafer include means for cutting the semiconductor wafer based at least in part on the location of the at least one alignment feature.

16. An apparatus for singulating semiconductor dies, comprising:
a detection device having a semiconductor workpiece support and a detector positioned proximate to the support, the detector being positioned to receive a signal corresponding to a location of an irregularly spaced die of the workpiece;
a singulation device; and
a controller operatively coupled to the detection device and the singulation device, the controller having instructions directing relative motion between the singulation device and the workpiece support based at least in part on information received from the detector corresponding to the location of the irregularly spaced die of the workpiece.

17. The apparatus of claim 16 wherein the singulation device includes a blade cutter.

18. The apparatus of claim 16 wherein the singulation device and the workpiece support are not rotatable relative to each other.

19. The apparatus of claim 16 wherein the controller has instructions directing a change in a width of a kerf made by the singulation device, based at least in part on information received from the detector.

20. The apparatus of claim 16 wherein the controller has instructions directing the singulation device to make multiple cuts along a single street, based at least in part on information received from the detector.

21. The apparatus of claim 16 wherein the controller has instructions directing the singulation device to make a first cut and a second

Assignees

• Micron Technology Inc

Inventors

• Farnworth Warren M
• Muntifering Tom A
• Clawson Paul J

Classifications

• H10P54/00 Primary

  Cutting or separating of wafers, substrates or parts of devices · CPC title

• H10P74/23 Primary

  characterised by multiple measurements, corrections, marking or sorting processes · CPC title

• B23K2203/50

  Operations & Transport · mapped topic

• B23K26/042

  Automatically aligning the laser beam · CPC title

• B26F3/004

  by means of a fluid jet (methods for use of abrasive blasting for cutting B24C1/045; guns for abrasive fluid jets B24C5/02; perforating by non-mechanical means, e.g. by fluid jet B26F1/26) · CPC title