Methods for fabrication of semiconductor structures using laser lift-off process, and related semiconductor structures

Patent metadata

Field	Value
Publication number	US-9728458-B2
Application number	US-201314416895-A
Country	US
Kind code	B2
Filing date	Jul 8, 2013
Priority date	Jul 31, 2012
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

Methods of fabricating a semiconductor structure include bonding a carrier wafer over a substrate, removing at least a portion of the substrate, transmitting laser radiation through the carrier wafer and weakening a bond between the substrate and the carrier wafer, and separating the carrier wafer from the substrate. Other methods include forming circuits over a substrate, forming trenches in the substrate to define unsingulated semiconductor dies, bonding a carrier substrate over the unsingulated semiconductor dies, transmitting laser radiation through the carrier substrate and weakening a bond between the unsingulated semiconductor dies and the carrier substrate, and separating the carrier substrate from the unsingulated semiconductor dies. Some methods include thinning at least a portion of the substrate, leaving the plurality of unsingulated semiconductor dies bonded to the carrier substrate.

First claim

What is claimed is:

1. A method of fabricating a semiconductor structure, comprising:
forming a plurality of active components over a substrate;
removing first portions of the substrate from an upper surface of the substrate at which the active components are located by forming trenches extending from the upper surface partially through the substrate at locations between adjacent active components of the plurality of active components;
after forming the trenches, bonding a carrier wafer over the active components and covering the trenches with the carrier substrate;
removing a second portion of the substrate and exposing the trenches by thinning the substrate, thinning the substrate comprising using one or more of a grinding process, a polishing process, and an etching process to remove a layer of material of the substrate having a thickness of about 500 μm or more from a lower surface of the substrate, the lower surface of the substrate opposite the upper surface of the substrate;
transmitting laser radiation at a lasing wavelength in a range extending from about 475 nm to about 650 nm through the carrier wafer and weakening a bond between the substrate and the active components; and
separating the carrier wafer from the substrate.

2. The method of claim 1 , wherein transmitting laser radiation through the carrier wafer and weakening a bond between the substrate and the active components comprises exposing the carrier wafer to radiation at a lasing wavelength and transmitting at least about 95% of the radiation at the lasing wavelength.

3. The method of claim 2 , wherein transmitting at least about 95% of the radiation at the lasing wavelength comprises transmitting at least about 99% of the radiation at the lasing wavelength.

4. The method of claim 1 , wherein separating the carrier wafer from the substrate comprises separating the carrier wafer from the substrate without consuming the carrier wafer.

5. A method of fabricating semiconductor structures, comprising:
forming a plurality of circuits over a substrate, the plurality of circuits each comprising at least one active component;
forming trenches extending partially through the substrate from an upper surface of the substrate so as to define a plurality of semiconductor dies, each semiconductor die of the plurality comprising a circuit of the plurality and a portion of the substrate;
after forming the trenches, bonding a carrier substrate over the semiconductor dies and covering the trenches with the carrier substrate;
thinning the substrate and exposing the trenches by thinning the substrate and laterally isolating the semiconductor dies bonded to the carrier substrate, thinning the substrate comprising removing a layer of material of the substrate having a thickness of about 500 μm or more from a lower surface of the substrate opposite the upper surface of the substrate, each of the laterally isolated semiconductor dies comprising a thinned portion of the substrate and a circuit of the plurality on the thinned portion of the substrate;
transmitting laser radiation at a lasing wavelength in a range extending from about 475 nm to about 650 nm through the carrier substrate and weakening a bond between the laterally isolated semiconductor dies and the carrier substrate; and
separating the carrier substrate from the laterally isolated semiconductor dies.

6. The method of claim 5 , wherein separating the carrier substrate from the laterally isolated semiconductor dies comprises separating the carrier substrate from the laterally isolated semiconductor dies without consuming the carrier substrate.

7. The method of claim 5 , wherein bonding a carrier substrate over the laterally isolated semiconductor dies comprises bonding a transparent carrier substrate to the upper surface of the laterally isolated semiconductor dies.

8. The method of claim 5 , wherein transmitting laser radiation through the carrier substrate and weakening a bond between the laterally isolated semiconductor dies and the carrier substrate comprises transmitting radiation at a lasing wavelength in a range from about 150 nm to about 750 nm through the carrier substrate.

9. A method of fabricating semiconductor structures, comprising:
forming trenches extending from an upper surface of a substrate partially through the substrate between semiconductor dies formed on or in the substrate, each of the semiconductor dies comprising at least one active component;
after forming the trenches, bonding a carrier substrate to the upper surface of each of the semiconductor dies and covering the trenches with the carrier substrate;
removing a layer of material of the substrate having a thickness of about 500 μm or more from a lower surface of the substrate opposite the upper surface of the substrate so as to thin the substrate, expose the trenches, and laterally isolate the semiconductor dies from one another, leaving the laterally isolated semiconductor dies bonded to the carrier substrate;
transmitting laser radiation at a lasing wavelength in a range extending from about 475 nm to about 650 nm through the carrier substrate and weakening a bond between the semiconductor dies and the carrier substrate; and
separating the carrier substrate from the semiconductor dies so as to singulate the semiconductor dies.

10. The method of claim 9 , wherein bonding a carrier substrate to the upper surface of each of the semiconductor dies comprises bonding a transparent wafer to the upper surface of each of the semiconductor dies.

11. The method of claim 9 , further comprising:
forming trenches extending partially through another substrate from an upper surface of the another substrate to define additional semiconductor dies;
after forming the trenches, bonding the carrier substrate to the upper surface of each of the additional semiconductor dies and covering the trenches with the carrier substrate;
removing material of the another substrate from a lower surface of the another substrate opposite the upper surface of the another substrate so as to thin the another substrate, expose the trenches, and laterally isolate the additional semiconductor dies from one another, leaving the laterally isolated additional semiconductor dies bonded to the carrier substrate;
transmitting laser radiation through the carrier substrate and weakening a bond between the additional semiconductor dies and the carrier substrate; and
separating the carrier substrate from the additional semiconductor dies so as to singulate the additional semiconductor dies.

12. The method of claim 9 , wherein separating the carrier substrate from the semiconductor dies comprises separating the carrier substrate without consuming the carrier substrate.

13. The method of claim 9 , wherein transmitting laser radiation through the carrier substrate and weakening a bond between the semiconductor dies and the carrier substrate comprises raster scanning a laser with respect to the carrier substrate.

Assignees

• Soitec Silicon On Insulator

Inventors

• Sadaka Mariam
• Aspar Bernard
• Blanchard Chrystelle Lagahe

Classifications

• H10P95/112

  leaving a reusable substrate, e.g. epitaxial lift off · CPC title

• H10P72/74

  using temporarily an auxiliary support · CPC title

• H10P52/00

  Grinding, lapping or polishing of wafers, substrates or parts of devices · CPC title

• H10P34/42

  with electromagnetic radiation, e.g. laser annealing (laser cutting H10P54/20) · CPC title

• H10P54/00 Primary

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