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EP0987741A1 Expired / Lapsed EP ⏱️ 0.0 years remaining

Method for relieving stress in GaN devices

Assignee: Lumileds LLC
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Filing: 1999-07-08
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Granted: —
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Expires: 2019-07-08
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Abstract

Abstract An improved method for growing a first layer[10, 30] on a second layer[12, 32] in which the first and second layers have different thermal indices of expansion and/or a mismatch of the lattice constants and the deposition being carried out at a temperature above ambient. The first layer[10, 30] includes a material that decomposes upon heating above a decomposition temperature. One of the first and second layers absorbs light in a first frequency range and the other of the first and second layers is transparent to the light in the first frequency range. In the method of the present invention, the one of the first and second layers that absorbs light in the first frequency range is exposed to light[14] in the first frequency range by passing the light through the other of the first and second layers. This exposure heats the first layer[10, 30] to a temperature above the decomposition temperature at the interface of the first and second layers after the first layer[10, 30] has been deposited on the second layer[12,32]. The decomposition can also mean to physically remove the material by means such as chemical etching. The present invention is well suited to the deposition of III-V semiconducting materials on substrates such as sapphire.

Inventors

  • 👤 Shih-Yuan Wang
  • 👤 Yong Chen

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-02 07:38
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/20; H10P14/38; H10P14/3822; H10P14/29; H10P14/2901; H10P14/2902; H10P14/2905; H10P14/2921; H10P14/32; H10P14/3202; H10P14/3204; H10P14/3208; H10P14/34; H10P14/3402; H10P14/3414; H10P14/3416

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 83 words
In a method for depositing a first layer[10, 30] on a second layer[10, 32] wherein said first and second layers have different thermal indices of expansion and/or lattice constants, the improvement comprising the step of decomposing a portion[11] of one of said first and second layers after said first layer[10, 30] has been deposited on said second layer[10, 32], said decomposed portion[11] comprising a portion of said one of said first and second layers at the interface of said first and second layers.
Claim 2
Dependent Claim 43 words
The method of Claim 1 wherein said step of decomposing a portion of one of said first and second layers comprises etching holes[32] in said second layer[12,32] from the side of said second layer[12,32] that is not in contact with said first layer[10,30].
Claim 3
Dependent Claim 166 words
The method of Claim 1 or 2 wherein said one of said first and second layers that is decomposed is said first layer[10, 30], said first layer[10, 30] comprising a material that decomposes upon heating above a decomposition temperature, wherein one of said first and second layers absorbs light in a first frequency range and the other of said first and second layers is transparent to said light in said first frequency range, and wherein said step of decomposing said portion of said one of said first and second layers comprises the step of exposing said one of said first and second layers that absorbs light in said first frequency range to light[14] in said first frequency range by passing said light through the other of said first and second layers thereby heating said first layer[10, 30] to a temperature above said decomposition temperature at the interface of said first and second layers after said first layer[10, 30] has been deposited on said second layer[10, 32].
Claim 4
Dependent Claim 14 words
The method of Claim 3 wherein said first layer[10, 30] comprises a III-V semiconductor.
Claim 5
Dependent Claim 11 words
The method of Claim 4 wherein said III-V semiconductor comprises GaN.
Claim 6
Dependent Claim 27 words
The method of Claim 4 or 5 wherein said second layer (10, 32) comprises a material chosen from the group consisting of sapphire, silicon, GaAs and InP.
Claim 7
Independent Claim 34 words
The method of one of Claims 3 to 6 wherein a portion of said first layer (10, 30) is not heated above said decomposition temperature at said interface between said first and second layers.
Claim 8
Independent Claim 54 words
The method of one of Claims 3 to 7 wherein said first layer (10, 30) is deposited at a temperature above ambient and wherein said first layer[10, 30] is heated to said temperature above said decomposition temperature before said first layer[10, 30] is returned to ambient after said first layer[10, 30] has been deposited.
Claim 9
Independent Claim 68 words
The method of one of Claims 3 to 8 wherein said first layer (10, 30) comprises a decomposition layer in contact with said substrate and a third layer, said second and third layers sandwiching said decomposition layer, said decomposition layer decomposing at a temperature less than the temperature at which said second and third layers decompose but greater than said temperature at which said deposition is carried out.

References Cited (Backward Citations)

EP0328405A2 Cited
US5141894A Cited
EP0871208A2 Cited

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