Granted Patent B2

US 7,514,721 · App. 11/290,299 · Granted Apr 7, 2009

Abstract

Claims (26)

1. A structure comprising:

a compound substrate comprising:

a host; and

a ceramic layer connected to the host, the ceramic layer containing a luminescent material and having a thickness less than 500 μm; and

a crystalline semiconductor structure attached to the compound substrate, the semiconductor structure including a light emitting layer disposed between an n-type region and a p-type region.

2. The structure of claim 1 wherein the ceramic layer has a thickness less than 250 μm.

3. The structure of claim 1 wherein the ceramic layer has a thickness less than 50 μm.

4. The structure of claim 1 wherein the host is one of single crystal Al 2 O 3 , polycrystalline Al 2 O 3 , AlN, Si, SiC, AlON, SiAlON, MgAl 2 O 4 , single crystal Y 3 Al 5 O 12 , ceramic Y 3 Al 5 O 12 , metal, and Mo.

5. The structure of claim 1 wherein the luminescent material is one of (Lu 1−x−y−a−b Y x Gd y ) 3 (Al 1−z−c Ga z Si c ) 5 O 12−c N c :Ce a Pr b wherein 0<x<1, 0<y<1, 0<z≦0.1, 0 <a ≦0.2, 0<b≦0.1, and 0<c<1; Lu 3 Al 5 O 12 :Ce 3+ ; Y 3 Al 5 O 12 :Ce 3+ ; Y 3 Al 4.8 Si 0.2 O 11.8 N 0.2 :Ce 3+ ; (Sr 1−x−y Ba x Ca y ) 2−z Si 5−a Al a N 8−a O a :Eu z 2+ wherein 0≦a<5, 0<x≦1, 0≦y≦1, and 0<z≦1; Sr 2 Si 5 N 8 :Eu 2+ ; (Sr 1−a−b Ca b Ba c )Si x N y O z ; Eu a 2+ (a=0.002−0.2, b=0.0−0.25, c=0.0−0.25, x=1.5−2.5, y=1.5−2.5, z=1.5−2.5); SrSi 2 N 2 O 2 ; Eu 2+ ; SrBaSiO 4 :Eu 2+ ; (Ca 1−x Sr x )S:Eu 2+ wherein 0≦x≦1; CaS:Eu 2+ ; SrS:Eu 2+ ; (Ca 1−x−y−z Sr x Ba y Mg z ) 1−n (Al 1−a+b B a )Si 1−b N 3−b O b :RE n , wherein 0≦x≦1, 0≦y≦1, 0≦z≦1, 0≦a≦1, 0<b≦1 and 0.002≦n≦0.2 and RE=Eu 2+ or Ce 3+ ; CaAlSiN 3 :Eu 2+ ; CaAl 1.04 Si 0.96 N 3 :Ce 3+ ; M x v+ Si 12−(m+n) Al m+n O n N 16−n , with x=m/v and M=Li, Mg, Ca, Y, Sc, Ce, Pr, Nf, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu or mixtures thereof; and Ca 0.75 Si 8.625 Al 3.375 O 1.375 N 0.625 :Eu 0.25 .

6. The structure of claim 1 wherein:

the light emitting layer is configured to emit light of a first peak wavelength when forward biased; and

the luminescent material is capable of absorbing light of the first peak wavelength and emitting light of a second peak wavelength.

7. The structure of claim 1 wherein the semiconductor structure is grown over the compound substrate.

8. The structure of claim 1 wherein the compound substrate further comprises a seed layer, wherein:

the ceramic layer is disposed between the host and the seed layer; and

the semiconductor structure is grown directly on the seed layer.

9. The structure of claim 8 wherein the seed layer is one of GaN, 4H SiC, 6H SiC, ScMgAlO 4 , ZnO, Al 2 O 3 , AlGaN, and InGaN.

10. The structure of claim 8 further comprising a bonding layer disposed between the seed layer and the ceramic layer, wherein the bonding layer attaches the seed layer to the ceramic layer.

11. The structure of claim 1 wherein the semiconductor structure is grown on a growth substrate and bonded to the compound substrate by a bond at an interface between the ceramic layer and the semiconductor structure.

12. The structure of claim 11 further comprising a bonding layer disposed between the ceramic layer and the semiconductor structure.

13. The structure of claim 11 wherein the growth substrate is one of SiC and Al 2 O 3 .

14. The structure of claim 1 further comprising:

a first contact electrically connected to the p-type region; and

a second contact electrically connected to the n-type region;

wherein the first and second contacts are both formed on a same side of the semiconductor structure.

15. The structure of claim 1 further comprising a cover overlying the light emitting layer.

Assignments (6)