Solid state lighting devices with current routing and associated methods of manufacturing
View Patent ↗Solid state lighting (“SSL”) devices with improved contacts and associated methods of manufacturing are disclosed herein. In one embodiment, an SSL device includes a first semiconductor material, a second semiconductor material spaced apart from the first semiconductor material, and an active region between the first and second semiconductor materials. The SSL device also includes a first contact on the first semiconductor material and a second contact on the second semiconductor material. The second contact is opposite the first contact. The SSL device further includes an insulative material between the first contact and the first semiconductor material, the insulative material being generally aligned with the second contact.
1. A solid state lighting (SSL) device, comprising:
a first semiconductor material;
a second semiconductor material spaced apart from the first semiconductor material;
an active region between the first and second semiconductor materials;
a first contact on the first semiconductor material;
a second contact on the second semiconductor material, the second contact being opposite the first contact;
a first insulative material between the first contact and the first semiconductor material, the first insulative material being aligned with the second contact; and
a second insulative material between at least one of the first semiconductor material and the active region and/or the second semiconductor material and the active region, wherein the second insulative material is aligned with the first insulative material and separated from the first insulative material by at least the first semiconductor material.
2. The SSL device of claim 1 wherein:
the second contact includes a contact finger with a first width;
the first semiconductor material includes a P-type gallium nitride (GaN) material;
the second semiconductor material includes an N-type GaN material;
the active region includes at least one of a bulk indium gallium nitride (InGaN) material, an InGaN single quantum well (“SQW”), and GaN/InGaN multiple quantum wells (“MQWs”);
the first contact includes a conductive material having an aperture extending from the first semiconductor material into the conductive material;
the conductive material includes aluminum (Al);
the aperture has a shape similar to that of the contact finger of the second contact;
the aperture contains the first insulative material;
the first insulative material includes silicon dioxide (SiO2); and
the aperture has a second width larger than the first width.
3. The SSL device of claim 1 wherein:
the second contact includes a contact finger with a first width;
the first semiconductor material includes a P-type gallium nitride (GaN) material;
the second semiconductor material includes an N-type GaN material;
the active region includes at least one of a bulk indium gallium nitride (InGaN) material, an InGaN single quantum well (“SQW”), and GaN/InGaN multiple quantum wells (“MQWs”);
the first contact includes a conductive material having an aperture extending from the first semiconductor material into the conductive material;
the aperture has a shape similar to that of the contact finger of the second contact;
the aperture contains the first insulative material; and
the aperture has a second width generally equal to the first width.
4. The SSL device of claim 1 wherein:
the second contact includes a contact finger with a first width;
the first semiconductor material includes a P-type gallium nitride (GaN) material;
the second semiconductor material includes an N-type GaN material;
the active region includes at least one of a bulk indium gallium nitride (InGaN) material, an InGaN single quantum well (“SQW”), and GaN/InGaN multiple quantum wells (“MQWs”);
the first contact includes a conductive material having an aperture extending from the first semiconductor material into the conductive material;
the aperture has a shape similar to that of the contact finger of the second contact;
the aperture contains the first insulative material; and
the aperture has a second width greater than the first width.
5. The SSL device of claim 1 wherein:
the second contact includes a contact finger with a first width;
the first semiconductor material includes a P-type gallium nitride (GaN) material;
the second semiconductor material includes an N-type GaN material;
the active region includes at least one of a bulk indium gallium nitride (InGaN) material, an InGaN single quantum well (“SQW”), and GaN/InGaN multiple quantum wells (“MQWs”);
the first contact includes a conductive material having an aperture extending from the first semiconductor material into the conductive material;
the aperture has a shape similar to that of the contact finger of the second contact;
the aperture contains the first insulative material; and
the aperture has a second width smaller than the first width.
6. The SSL device of claim 1 wherein:
the first contact includes a conductive material having an aperture extending from the first semiconductor material into the conductive material; and
the aperture contains the first insulative material.
7. The SSL device of claim 1 wherein:
the first contact includes a conductive material having an aperture extending from the first semiconductor material into the conductive material;
the aperture has a shape similar to that of the second contact; and
the aperture contains the first insulative material.
8. The SSL device of claim 1 wherein:
the second contact includes a contact finger;
the first contact includes a conductive material having an aperture extending from the first semiconductor material into the conductive material;
the aperture has a shape similar to that of the contact finger of the second contact; and
the aperture contains the first insulative material.
9. A solid state lighting (SSL) device, comprising:
a first semiconductor material;
a second semiconductor material spaced apart from the first semiconductor material;
an active region between the first and second semiconductor materials;
a first contact on the first semiconductor material;
a second contact on the second semiconductor material, the second contact being opposite the first contact;
a current router between the first contact and the first semiconductor material, the current router being configured to decrease a first current flow in a first area superimposed with the second contact and increase a second current flow in a second area generally offset from the second contact;
a first insulative material between the first semiconductor material and the first contact, the first insulative material being aligned with the second contact; and
a second insulative material between at least one of the first semiconductor material and the active region and/or the second semiconductor material and the active region, wherein the second insulative material is aligned with the first insulative material and separated from the first insulative material by at least the first semiconductor material.
10. The SSL device of claim 9 wherein the current router includes a conductive material between the first semiconductor material and the first contact, the conductive material being offset from the second contact.
11. The SSL device of claim 9 wherein the current router includes a conductive material and a first insulative material between the first semiconductor material and the first contact, the conductive material being offset from the second contact, and the first insulative material being aligned with the second contact.
12. A method of forming a solid state lighting (SSL) device, comprising:
forming an SSL structure having a first semiconductor material, a second semiconductor material spaced apart from the first semiconductor material, and an active region between the first and second semiconductor materials;
forming a first contact on the first semiconductor material;
forming a first insulative material between at least one of the first semiconductor material and the active region and/or the second semiconductor material and the active region,
forming a current router on the second semiconductor material, the current router being aligned with the first contact and including a second insulative material aligned with the first insulative material and separated from the first insulative material by at least the first semiconductor material; and
forming a second contact on the second semiconductor material and on the current router.
13. The method of claim 12 wherein forming the second contact includes encapsulating the current router with a conductive material.
14. The method of claim 12 wherein:
forming the second contact includes encapsulating the second insulative material with a conductive material; and
the conductive material includes a first portion and a second portion, the first portion being separated from the second semiconductor material by the second insulative material, the second portion being in contact with the second semiconductor material.
15. The method of claim 12 wherein:
forming the current router includes:
blanketing the second semiconductor material with the second insulative material;
depositing a masking material onto the second insulative material;
patterning the masking material to define an opening;
removing a portion of the second insulative material to form the aperture; and
forming the second contact includes encapsulating the second insulative material with a conductive material, the conductive material including a first portion and a second portion, the first portion being on the second insulative material, and the second portion being in the aperture.
16. The method of claim 12 wherein:
forming the current router includes:
blanketing the second semiconductor material with a contact material;
depositing a masking material onto the blanketing contact material;
patterning the masking material to define an opening;
removing a portion of the contact material to form the aperture, the aperture being offset from the first contact; and
forming the second contact includes encapsulating the contact material with a conductive material, the conductive material including a first portion and a second portion, the first portion being on the contact material, and the second portion being in the aperture, wherein the contact material has contact resistance lower than that of the conductive material.