Method for nondestructive lift-off of GaN from sapphire substrate utilizing a solid-state laser
First Claim
1. A method for non-destructively lifting a III-V semiconductor device from a sapphire substrate, comprising:
- obtaining a III-V semiconductor layer grown on a sapphire substrate at an interface;
irradiating a laser beam through the sapphire substrate, wherein the laser beam forms a laser spot at the interface between the III-V semiconductor layer and the sapphire substrate, wherein the laser spot has a distance between two farthest corners or a longest diameter smaller than 400 μ
m; and
scanning the laser beam across the interface between the III-V semiconductor layer and the sapphire substrate to form a plurality of laser spots at the interface to non-destructively separate the III-V semiconductor layer from the sapphire substrate, wherein the distance between the centers of adjacent laser spots at the interface is in a range of about 30 μ
m and about 100 μ
m.
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Abstract
A method for nondestructive laser lift-off of GaN from sapphire substrates is disclosed. A solid-state laser is used as the laser source. A small laser-spot having a perimeter length of 3 to 1000 micrometers and a distance of two farthest corners or a longest diameter of no more than 400 micrometers is used for laser scanning point-by-point and line-by-line. The energy at the center of the laser-spot is the strongest and is gradually reduced toward the periphery. A nondestructive laser lift-off with a small laser-spot is achieved. The scanning mode of the laser lift-off is improved. Device lift-off can be achieved without the need of aiming. As a result, the laser lift-off process is simplified, and the efficiency is improved while the rejection rate is reduced. The obstacles of the industrialization of the laser lift-off process are removed.
8 Citations
19 Claims
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1. A method for non-destructively lifting a III-V semiconductor device from a sapphire substrate, comprising:
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obtaining a III-V semiconductor layer grown on a sapphire substrate at an interface; irradiating a laser beam through the sapphire substrate, wherein the laser beam forms a laser spot at the interface between the III-V semiconductor layer and the sapphire substrate, wherein the laser spot has a distance between two farthest corners or a longest diameter smaller than 400 μ
m; andscanning the laser beam across the interface between the III-V semiconductor layer and the sapphire substrate to form a plurality of laser spots at the interface to non-destructively separate the III-V semiconductor layer from the sapphire substrate, wherein the distance between the centers of adjacent laser spots at the interface is in a range of about 30 μ
m and about 100 μ
m. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A method for non-destructively lifting a III-V semiconductor device from a sapphire substrate, comprising:
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obtaining a III-V semiconductor layer grown on a sapphire substrate at an interface; irradiating a laser beam through the sapphire substrate, wherein the laser beam forms a laser spot at the interface between the III-V semiconductor layer and the sapphire substrate, wherein the perimeter of the laser spot has a length between about 3 μ
m and 1000 μ
m; andscanning the laser beam across the interface between the III-V semiconductor layer and the sapphire substrate to form a plurality of laser spots at the interface to non-destructively separate the III-V semiconductor layer from the sapphire substrate, wherein the distance between the centers of adjacent laser spots at the interface is in a range of about 30 μ
m and about 100 μ
m. - View Dependent Claims (17, 18, 19)
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Specification