Edge seal for a semiconductor device and method therefor
View Patent ↗In one embodiment, an edge seal region of a semiconductor die is formed by forming a first dielectric layer on a surface of a semiconductor substrate near an edge of the semiconductor die and extending across into a scribe grid region of the semiconductor substrate. Another dielectric layer is formed overlying the first dielectric layer. An opening is formed through the first and second dielectric layers. The second dielectric layer is used as a mask for forming a doped region on the semiconductor substrate through the opening. A metal is formed that electrically contacts the doped region and an exterior edge of the first dielectric layer within the opening.
1. A method of forming an edge seal region of a semiconductor die comprising:
forming a first dielectric layer on a substrate adjacent to a scribe grid area of the substrate;
forming a second dielectric layer overlying the first dielectric layer;
forming a doped region on the substrate and self-aligned to an edge of the second dielectric layer; and
forming a metal spacer on the doped region and self-aligned to an edge of the first dielectric layer.
2. The method of claim 1 wherein forming the doped region on the substrate includes forming a passivation layer overlying the second dielectric layer and using the passivation layer as a mask to form an opening through the second dielectric layer and the first dielectric layer and further including forming the doped region through the opening then forming the metal spacer through the opening.
3. The method of claim 1 wherein forming the metal spacer includes forming the metal spacer and leaving a surface of the substrate that is abutting the metal spacer and distal from the first dielectric layer exposed, and further including cutting through the substrate where the surface of the substrate is exposed.
4. The method of claim 1 further including forming active regions of the semiconductor die in an interior section of the semiconductor die before the step of forming the doped region on the substrate wherein forming the active regions include forming active doped regions and activating dopants within the active doped regions;
wherein the step of forming the doped region includes not performing an activation step after forming the doped region on the substrate; and
wherein the step of forming the metal spacer includes not exposing the semiconductor die to a temperature that is greater than a temperature required to sinter the metal spacer.
5. The method of claim 1 wherein forming the metal spacer includes forming a metal layer overlying the second dielectric layer and on the substrate overlying the doped region; and anisotropicallv etching the metal layer to remove first portions of the metal layer and leave second portions of the metal abutting the edge of the first dielectric layer as the spacers.
6. The method of claim 1 wherein forming the doped region on the substrate includes forming an opening through the first and second dielectric layers and exposing the substrate, and forming the doped region through the opening subsequent to the step of forming the second dielectric layer.