Patent ID: 11916169
Assignee: PLESSEY SEMICONDUCTORS LIMITED
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 8:
9. An active matrix LED array precursor according to claim 1, wherein the monolithic LED structure comprises:
(i) a second semiconductor layer on the common first semiconductor layer, having an upper surface portion parallel to the plane of the LED array precursor, the second semiconductor layer having a regular trapezoidal cross-section normal to the upper surface portion, such that the second semiconductor layer has sloped sides;
(ii) a third semiconductor layer on the second semiconductor layer, having an upper surface portion parallel to the plane of the LED array precursor, the third semiconductor layer formed on the second semiconductor layer such that the second and third semiconductor layers have a regular trapezoidal cross-section normal to the upper surface portion, such that the third semiconductor layer has sloped sides parallel to the sloped sides of the second semiconductor layer;
(iii) a fourth semiconductor layer on the third semiconductor layer, having an upper surface portion parallel to the plane of the LED array precursor, the fourth semiconductor layer formed on the third semiconductor layer such that the second, third, and fourth semiconductor layers have a regular trapezoidal cross-section normal to the upper surface portion, such that the fourth semiconductor layer has sloped sides parallel to the sloped sides of the third semiconductor layer; and
(iv) a primary electrical contact on the fourth semiconductor layer, wherein the contact is only on the upper surface portion of the fourth semiconductor layer which is parallel to the plane of the LED array precursor;
wherein the first to fourth semiconductor layers comprise Group III-nitrides, and the third semiconductor layer comprises a plurality of quantum well sub-layers, the quantum well sub-layers having a greater thickness on a portion parallel to the plane of the LED array precursor and a reduced thickness on a portion which is not parallel to the plane of the LED array precursor.