Patent ID: 9111809
Filing Date: 2015-08-18
Classification: H01L

Abstract:
1. A circuit substrate comprising: a plurality of devices having drain electrodes; a plurality of conductive layers connected in one-to-one correspondence with the devices; and an insulating layer provided between the devices and the conductive layers, the devices, the conductive layers, and the insulating layer being provided on an insulating substrate, wherein the insulating layer includes a first insulating layer covering the devices, a second insulating layer formed on the first insulating layer, and a plurality of contact holes each passing through the first insulating layer and the second insulating layer in a thickness direction thereof, wherein inside each one of the plurality of contact holes a first side surface of the first insulating layer forming a first part of a side surface of said one of the plurality of contact holes and a second side surface of the second insulating layer forming a second part of the side surface of said one of the plurality of contact holes contact each other inside said one of the plurality of contact holes, wherein the conductive layers are formed so that each of the conductive layers extends along an upper surface of the second insulating layer, at least part of the side surface of said one of the plurality of contact holes at which the first side surface and the second side surface contact each other, and a bottom surface of the contact hole, wherein each of the first side surface and the second side surface has a loop shape having a longitudinal direction and a lateral direction when viewed from a direction normal to the insulating substrate, wherein a part of the first side surface extending in the longitudinal direction and a part of the second side surface extending in a longitudinal direction contact each other, wherein an inclination angle of the first side surface is more gentle in the longitudinal direction than in the lateral direction, wherein the first insulating layer is arranged on the drain electrode, and wherein one of the conductive layers is arranged on the drain electrode and is sandwiched between portions of the first layer, and wherein a width of said one of the conductive layers is greater in the longitudinal direction than in the lateral direction.