Method for forming interconnect bumps on a semiconductor die
AssigneeMotorola, Inc.
InventorsRobert A. Munroe, Stuart E. Greer
Life of this patent
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Abstract
A method of forming an interconnect bump structure (32, 33). Under Bumb Metalization 11 (UBM) comprising a chrome layer (16), a copper layer (36), and a tin layer (40) is disclosed. In one embodiment, eutectic solder (45) is then formed over the UBM (11) and reflowed in order to form the interconnect bump stucture. In another embodement, a lead standoff (46) is formed over the UBM (11) before the formation of the eutectic solder (48).
Claims24
A method for forming conductive bumps on a semiconductor device comprising:
- providing a semiconductor die having a plurality of bump pads;
- forming a seed layer over each of the plurality of bump pads;
- forming a tin layer over the seed layer;
- depositing a eutectic layer over each of the plurality of bump pads such that the eutectic layer directly covers the tin layer;
- and
- reflowing the eutectic layer after depositing the eutectic layer.
A method of forming conductive bumps on a semiconductor device, the method comprising:
- providing a semiconductor device having an interconnect location;
- forming a seed layer over the interconnect location;
- forming a first layer comprising copper over the seed layer;
- forming a second layer comprising tin using an evaporative process over the first layer;
- forming a third layer comprising lead using an evaporative process, wherein the lead forms a stand-off structure;
- depositing a fourth layer comprising a eutectic material over the third layer;
- reflowing the fourth layer after depositing the fourth layer to form a eultectic bump over the interconnect location, wherein the fourth layer substantially surrounds the stand-off structure following reflow.
A method of forming a semiconductor device, the method comprising:
- forming a chrome layer over a conductive interconnect pad of a semiconductor die;
- forming a copper layer directly over the chrome layer;
- forming a tin layer over the copper layer;
- depositing a high tin content tin-lead eutectic solder over the tin layer;
- reflowing the high tin content tin-lead solder to form a solder ball after depositing the high tin content tin-lead eutectic solder.
A method of forming conductive bumps on a semiconductive bumps on a semiconductor device, the method comprising:
- providing a semiconductor device having an interconnect location;
- forming a seed layer over the interconnect location;
- forming a first layer comprising copper over the seed layer;
- forming a second layer comprising tin using an evaporative process over the first layer;
- forming a third layer comprising lead using an evaporative process;
- forming a fourth layer comprising tin;
- reflowing the third and fourth layer to form a eutectic portion directly over and contacting the second layer.
Dependencies are inferred from the claim text.