Semiconductor device and a method for making the semiconductor device
View Patent ↗An opening ( 9 ) is made in the substrate ( 1 ) over a terminal pad ( 7 ). A dielectric layer ( 10 ), a metallization ( 11 ), a compensation layer ( 13 ) and a passivation layer ( 15 ) are deposited so that the passivation layer is separated from the metallization by the compensation layer at least within the opening. A material that is suitable for reducing a mechanical stress between the metallization and the passivation layer is chosen for the compensation layer.
1. A method for producing a semiconductor device, comprising the steps of:
providing a substrate of a semiconductor material with a buried terminal pad of electrically conductive material;
removing, from an upper side of the substrate, the semiconductor material over the terminal pad to make an opening;
depositing a dielectric layer;
within the opening, exposing the terminal pad;
depositing a metallization, which contacts the terminal pad and is separated from the substrate by the dielectric layer;
depositing a compensation layer, which completely covers the metallization within the opening, on a bottom of the opening, on side walls of the opening and on a region of an upper side of the device along the rim of the opening and outside of the opening; and
depositing a passivation layer, which is separated from the metallization by the compensation layer within the opening, into the opening and on the upper side of the device outside of the opening,
wherein the compensation layer is a polymer.
2. The method of claim 1 , in which the compensation layer is a polyimide.
3. The method of claim 1 , further comprising:
removing the metallization outside of the opening before deposition of the compensation layer,
depositing a top metal, which contacts the upper rim of the metallization, and
forming the compensation layer so that the metallization is completely covered.
4. The method according to claim 1 , further comprising:
removing the semiconductor material in a backside region of the substrate that is opposite to the opening, and
forming a backside via extending to the terminal pad.
5. The method according to claim 1 , wherein the passivation layer is made of at least two layers of different materials.
6. The method of claim 5 , wherein the passivation layer is made by first depositing an oxide layer and then depositing a nitride layer on the oxide layer.