Pad structure including glue layer and non-low-k dielectric layer in BSI image sensor chips

摘要

An integrated circuit structure includes a semiconductor substrate, and a dielectric pad extending from a bottom surface of the semiconductor substrate up into the semiconductor substrate. A low-k dielectric layer is disposed underlying the semiconductor substrate. A first non-low-k dielectric layer is underlying the low-k dielectric layer. A metal pad is underlying the first non-low-k dielectric layer. A second non-low-k dielectric layer is underlying the metal pad. An opening extends from a top surface of the semiconductor substrate down to penetrate through the semiconductor substrate, the dielectric pad, and the low-k dielectric layer, wherein the opening lands on a top surface of the metal pad. A passivation layer includes a portion on a sidewall of the opening, wherein a portion of the passivation layer at a bottom of the opening is removed.

主权项

1. An integrated circuit structure comprising:
a semiconductor substrate comprising a front side and a backside; a metal shield on the backside of the semiconductor substrate; a low-k dielectric layer on the front side of the semiconductor substrate; a non-low-k dielectric layer on the low-k dielectric layer; a metal pad on the non-low-k dielectric layer;
an opening extending from the backside of the semiconductor substrate to penetrate through the semiconductor substrate the non-low-k dielectric layer and the low-k dielectric layer, wherein the opening exposes a surface of the metal pad; a buffer layer directly adjoining a sidewall of the semiconductor substrate and extending over the metal shield; and a passivation layer formed on a sidewall and a bottom of the opening, wherein the passivation layer at the bottom of the opening partially covers the exposed surface of the metal pad, wherein the passivation layer extends over the metal shield and a portion of the buffer layer.