Lumileds LLC

Koninklijke Philips Corporation N.v.

Quanbo Zou

Salman Akram

Jerome Chandra Bhat

Minh Ngoc Trieu

Robert Blank

Jerome Chanra Bhat

Jérôme Chandra Bhat

A method according to embodiments of the invention includes providing a wafer of semiconductor devices grown on a growth substrate. The wafer of semiconductor devices has a first surface and a second surface opposite the first surface. The second surface is a surface of the growth substrate. The method further includes bonding the first surface to a first wafer and bonding the second surface to a second wafer. In some embodiments, the first and second wafer each have a different coefficient of thermal expansion than the growth substrate. In some embodiments, the second wafer may compensate for stress introduced to the wafer of semiconductor devices by the first wafer.

Method of bonding a semiconductor device to a support substrate

In one embodiment, a semiconductor device wafer () contains electrical components and has electrodes () on a first side of the device wafer (). A transparent carrier wafer () is bonded to the first side of the device wafer () using a bonding material () (e.g., a polymer or metal). The second side of the device wafer () is then processed, such as thinned, while the carrier wafer () provides mechanical support for the device wafer (). The carrier wafer () is then de-bonded from the device wafer () by passing a laser beam () through the carrier wafer (), the carrier wafer () being substantially transparent to the wavelength of the beam. The beam impinges on the bonding material (), which absorbs the beam's energy, to break the chemical bonds between the bonding material () and the carrier wafer (). The released carrier wafer () is then removed from the device wafer (), and the residual bonding material is cleaned from the device wafer ().

Laser de-bond carrier wafer from device wafer

Semiconductor LED layers are epitaxially grown on a patterned surface of a sapphire substrate. The patterned surface improves light extraction. The LED layers include a p-type layer and an n-type layer. The LED layers are etched to expose the n-type layer. One or more first metal layers are patterned to electrically contact the p-type layer and the n-type layer to form a p-metal contact and an n-metal contact. A dielectric polymer stress-buffer layer is spin-coated over the first metal layers to form a substantially planar surface over the first metal layers. The stress-buffer layer has openings exposing the p-metal contact and the n-metal contact. Metal solder pads are formed over the stress-buffer layer and electrically contact the p-metal contact and the n-metal contact through the openings in the stress-buffer layer. The stress-buffer layer acts as a buffer to accommodate differences in CTEs of the solder pads and underlying layers.

LED with stress-buffer layer under metallization layer

Semiconductor LED layers are epitaxially gown on a patterned surface of a sapphire substrate (). The patterned surface improves light extraction. The LED layers include a p-type layer and an n-type layer. The LED layers are etched to expose the n-type layer. One or more first metal layers are patterned to electrically contact the p-type layer and the n-type layer to form a p-metal contact () and an n-metal contact (). A dielectric polymer stress-buffer layer () is spin-coated over the first metal layers to form a substantially planar surface over the first metal layers. The stress-buffer layer has openings exposing the p-metal contact and the n-metal contact. Metal solder pads () are formed over the stress-buffer layer and electrically contact the p-metal contact and the n-metal contact through the openings in the stress-buffer layer. The stress-buffer layer acts as a buffer to accommodate differences in CTEs of the solder pads and underlying layers.

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Eindhoven, Netherlands

Quanbo Zou