Semiconductor device having under-bump metallization (UBM) structure and method of forming the same
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsTsung-Fu Tsai, Yian-Liang Kuo, Chih-Horng Chang
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Abstract
A semiconductor device comprises a semiconductor substrate, an under-bump metallization (UBM) structure overlying the semiconductor substrate, and a solder bump overlying and electrically connected to the UBM structure. The UBM structure comprises a copper-containing metallization layer, a nickel-containing metallization layer, and a first intermetallic compound (IMC) layer between the copper-containing metallization layer and the nickel-containing metallization layer. The first IMC layer is in direct contact with the copper-containing metallization layer and the nickel-containing metallization layer.
Claims20
A semiconductor device, comprising:
- a semiconductor substrate;
- an under-bump metallization (UBM) structure overlying the semiconductor substrate;
- and
- a solder bump overlying and electrically connected to the UBM structure;
- wherein the UBM structure comprises:
- a copper-containing metallization layer,
- a nickel-containing metallization layer, and
- a first intermetallic compound (IMC) layer between the copper-containing metallization layer and the nickel-containing metallization layer, the first IMC layer in direct contact with the copper-containing metallization layer and the nickel-containing metallization layer.
A method of forming a semiconductor device, said method comprising:
- forming a mask layer with an opening over a semiconductor substrate;
- forming a first metallization layer in the opening of the mask layer, wherein the first metallization layer comprises copper (Cu);
- forming a second metallization layer over the first metallization layer, wherein the second metallization layer comprises tin (Sn);
- forming a third metallization layer over the second metallization layer, wherein the third metallization layer comprises nickel (Ni);
- forming a solder layer overlying the third metallization layer;
- removing the mask layer;
- and
- performing a thermal reflow process on the solder layer, wherein
- the thermal reflow process forms a first intermetallic compound (IMC) layer between the first metallization layer and the third metallization layer, and
- the first IMC layer consumes at least a portion of the second metallization layer.
A method of forming a semiconductor device, said method comprising:
- forming a passivation layer overlying a semiconductor substrate, while exposing a portion of a pad region of the semiconductor substrate;
- forming a metallization layer over the passivation layer and the exposed portion of the pad region;
- forming a mask layer with an opening over the metallization layer;
- forming a copper (Cu) layer in the opening of the mask layer, the Cu layer having a thickness less than 10 μm;
- forming a tin (Sn) layer over the Cu layer, the Sn layer having a thickness less than ¾ of the thickness of the Cu layer;
- forming a nickel (Ni) layer over the Sn layer, the Ni layer having a thickness less than 10 μm;
- forming a solder layer over the Ni layer;
- removing the mask layer to expose a portion of the metallization layer;
- removing the exposed portion of the metallization layer;
- and
- performing a thermal reflow process on the solder layer.
Dependencies are inferred from the claim text.