Fabrication process for package with light emitting device on a sub-mount

A method of fabricating a package with a light emitting device on a sub-mount, the method comprising:

• depositing a first metallization to form a conductive pad on which the light emitting device is to be mounted and to form one or more feed-through interconnections extending through a semiconductor material that supports the conductive pad, wherein the first metallization is deposited so as to form respective overhangs around the top of the conductive pad and each of the one or more feed-through interconnections;
• subsequently depositing a second metallization to form a reflective surface for reflecting light, emitted by the light emitting device, through a lid of the package, wherein depositing the second metallization is de-coupled from depositing the first metallization, and wherein depositing the second metallization includes depositing the second metallization over a surface of the semiconductor material including over top surfaces of the conductive pad and the one or more feed-through interconnections, wherein the overhangs serve as shields to substantially prevent the second metallization from being deposited on areas directly below the overhangs;
• and
• subsequently removing the second metallization from top surfaces of the conductive pad and the one or more feed-through interconnections.

A method of fabricating a package to house a light emitting device, the method comprising:

• forming a cavity in a first side of a semiconductor wafer and forming one or more through-holes that extend from a bottom of the cavity to a second side of the wafer;
• depositing a first metallization to form a conductive pad for mounting the light emitting device and to form feed-through interconnections that extend through the one or more through-holes, wherein the first metallization is deposited so as to form respective overhangs around the top of the conductive pad and each of the feed-through interconnections;
• depositing a second metallization over the first side of the semiconductor wafer including over bottom and side surfaces of the cavity and over top surfaces of the conductive pad and the feed-through interconnections, wherein the overhangs serve as shields to substantially prevent the second metallization from being deposited on areas directly below the overhangs;
• selectively removing the second metallization from top surfaces of the conductive pad and the feed-through interconnections, so that the remaining second metallization forms a reflective surface that is electrically disconnected from the conductive pad and the feed-through interconnections;
• and
• mounting the light emitting device on the conductive pad.