Semiconductor light-emitting device, illuminator and method of manufacturing semiconductor light-emitting device
A semiconductor light-emitting device having high reliability is obtained while suppressing separation between a support substrate and a semiconductor element layer. This semiconductor light-emitting device includes a support substrate ( 1 ), a first bonding layer ( 2 a ) formed on the support substrate ( 1 ), a second bonding layer ( 2 b ) formed on the first bonding layer ( 2 a ), a third bonding layer ( 2 c ) formed on the second bonding layer ( 2 b ), and a semiconductor element layer ( 3 ) formed on the third bonding layer ( 2 c ). The melting point of the second bonding layer ( 2 b ) is lower than the melting points of the first bonding layer ( 2 a ) and the third bonding layer ( 2 c ).
1. A semiconductor light-emitting device comprising:
a support substrate ( 1 );
a first eutectic alloy layer ( 2 a ) formed on said support substrate;
a second eutectic alloy layer ( 2 b ) formed on said first eutectic alloy layer;
a third eutectic alloy layer ( 2 c ) formed on said second eutectic alloy layer; and
a semiconductor element layer ( 3 ) including an emission layer ( 3 d ) formed on said third eutectic alloy layer, wherein
the melting point of said second eutectic alloy layer is lower than the melting points of said first eutectic alloy layer and said third eutectic alloy layer, and
said third eutectic alloy layer is formed on the side surface of said semiconductor element layer through an insulating layer ( 4 ).
2. The semiconductor light-emitting device according to claim 1 , wherein
the thermal expansion coefficient of said second eutectic alloy layer is larger than the thermal expansion coefficients of said first eutectic alloy layer and said third eutectic alloy layer.
3. The semiconductor light-emitting device according to claim 1 , wherein
said first eutectic alloy layer, said second eutectic alloy layer and said third eutectic alloy layer contain at least any of an Au—Sn alloy, an Au—Ge alloy and an Au—Si alloy respectively.
4. The semiconductor light-emitting device according to claim 3 , wherein
said first eutectic alloy layer, said second eutectic alloy layer and said third eutectic alloy layer consist of the Au—Sn alloy, and
the content of Sn in said second eutectic alloy layer is larger than the contents of Sn in said first eutectic alloy layer and said third eutectic alloy layer.
5. The semiconductor light-emitting device according to claim 3 , wherein said first eutectic alloy layer and said third eutectic alloy layer consist of the Au—Ge alloy, and said second eutectic alloy layer consists of the Au—Sn alloy.
6. An illuminator comprising a semiconductor light-emitting device including:
a support substrate ( 1 );
a first eutectic alloy layer ( 2 a ) formed on said support substrate;
a second eutectic alloy layer ( 2 b ) formed on said first eutectic alloy layer;
a third eutectic alloy layer ( 2 c ) formed on said second eutectic alloy layer; and
a semiconductor element layer ( 3 ) including an emission layer ( 3 d ) formed on said third eutectic alloy layer, wherein
the melting point of said second eutectic alloy layer is lower than the melting points of said first eutectic alloy layer and said third eutectic alloy layer, and
said third eutectic alloy layer is formed on the side surface of said semiconductor element layer through an insulating layer ( 4 ).
7. The illuminator according to claim 6 , wherein
the thermal expansion coefficient of said second eutectic alloy layer is larger than the thermal expansion coefficients of said first eutectic alloy layer and said third eutectic alloy layer.
8. The illuminator according to claim 6 , wherein
said first eutectic alloy layer, said second eutectic alloy layer and said third eutectic alloy layer contain at least any of an Au—Sn alloy, an Au—Ge alloy and an Au—Si alloy respectively.
9. A method of manufacturing a semiconductor light-emitting device, comprising steps of:
forming a semiconductor element layer ( 3 ) including an emission layer ( 3 d );
arranging, between a support substrate ( 1 ) and said semiconductor element layer, a first eutectic alloy layer ( 2 a ), a second eutectic alloy layer ( 2 b ) and a third eutectic alloy layer ( 2 c ) in this order from the side of said support substrate; and
bonding said semiconductor element layer and said support substrate to each other through said first eutectic alloy layer, said second eutectic alloy layer and said third eutectic alloy layer by heating the same, wherein
the melting point of said second eutectic alloy layer is lower than the melting points of said first eutectic alloy layer and said third eutectic alloy layer, and
a heating temperature in the step of bonding said semiconductor element layer and said support substrate to each other is at least the melting point of said second eutectic alloy layer and less than the melting points of said first eutectic alloy layer and said third eutectic alloy layer, and
the step of arranging said first eutectic alloy layer, said second eutectic alloy layer and said third eutectic alloy layer includes a step of forming said third eutectic alloy layer on the side surface of said semiconductor element layer through an insulating layer.
10. The method of manufacturing a semiconductor light-emitting device according to claim 9 , wherein
the step of arranging said first eutectic alloy layer, said second eutectic alloy layer and said third eutectic alloy layer includes steps of:
forming said third eutectic alloy layer, said second eutectic alloy layer and said first eutectic alloy layer in this order on said semiconductor element layer, and
arranging said support substrate on said first eutectic alloy layer.
11. The method of manufacturing a semiconductor light-emitting device according to claim 9 , wherein
the step of arranging said first eutectic alloy layer, said second eutectic alloy layer and said third eutectic alloy layer includes steps of:
forming said third eutectic alloy layer, said second eutectic alloy layer and a part of said first eutectic alloy layer in this order on said semiconductor element layer,
forming another part of said first eutectic alloy layer on said support substrate, and
arranging the part of said first eutectic alloy layer formed on said support substrate on the part of said first eutectic alloy layer formed on said semiconductor element layer.
12. The method of manufacturing a semiconductor light-emitting device according to claim 9 , wherein
the step of forming said semiconductor element layer includes a step of forming said semiconductor element layer on a growth substrate ( 8 ),
the method further comprising a step of removing said growth substrate from said semiconductor element layer.
13. The method of manufacturing a semiconductor light-emitting device according to claim 9 , wherein
the thermal expansion coefficient of said second eutectic alloy layer is larger than the thermal expansion coefficients of said first eutectic alloy layer and said third eutectic alloy layer.
14. The method of manufacturing a semiconductor light-emitting device according to claim 9 , wherein
said first eutectic alloy layer, said second eutectic alloy layer and said third eutectic alloy layer contain at least any of an Au—Sn alloy, an Au—Ge alloy and an Au—Si alloy respectively.
15. The method of manufacturing a semiconductor light-emitting device according to claim 14 , wherein
said first eutectic alloy layer, said second eutectic alloy layer and said third eutectic alloy layer consist of the Au—Sn alloy, and
the content of Sn in said second eutectic alloy layer is larger than the contents of Sn in said first eutectic alloy layer and said third eutectic alloy layer.
16. The method of manufacturing a semiconductor light-emitting device according to claim 14 , wherein
said first eutectic alloy layer and said third eutectic alloy layer consist of the Au—Ge alloy, and
said second eutectic alloy layer consists of the Au—Sn alloy.