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US 6,426,556 B1Granted
Reliable metal bumps on top of I/O pads with test probe marks
AssigneeMegic Corporation
InventorMou-Shiung Lin
Life of this patent
Estimating the term…
Abstract
A new method is provided for the creation of metal bumps over surfaces of I/O pads. The area in the surface of I/O pads, which have been used for I/O pads during wafer level semiconductor device testing, is removed in the immediate vicinity of the surface area where the test probe contacts the I/O pad. This removal uses methods of metal dry etching or wet etching.
Claims66
A method for forming a metal bump on a semiconductor surface, comprising the steps of:
- providing a semiconductor surface, said semiconductor surface having been provided in or on the surface thereof with a contact pad, said contact pad sitting on an underlying layer of dielectric and being in electrical contact with at least one point of electrical contact in or on the surface of said substrate;
- depositing a layer of passivation over the surface of said layer of dielectric underlying the contact pad, including the surface of said contact pad;
- patterning and etching said layer of passivation, creating an opening in said layer of passivation having a first diameter, partially exposing the surface of said contact pad over a surface area of said first diameter, said first diameter of said opening created in said layer of passivation being smaller than a surface area of said contact pad by a measurable amount;
- patterning and etching said contact pad, creating an opening in said contact pad having a second diameter, said second diameter of said opening in said contact pad being smaller than said first diameter of said opening in said layer of passivation by a measurable amount;
- sputtering a layer of Under Bump Metallurgy (UBM) over the surface of said layer of passivation, including exposed surface of the contact pad and exposed surface of the underlying dielectric;
- depositing and patterning a layer of photoresist, creating an opening in the photoresist with a slightly larger dimension than said first diameter;
- electroplating a layer of bump metal in the photoresist opening;
- stripping the layer of photoresist and etching said layer of UBM, using said layer of bump metal as a mask;
- and
- reflowing the surface of said layer of bump metal, forming the metal bump.
7 more elements
A method for forming a metal bump on a semiconductor surface, comprising the steps of:
- providing a semiconductor surface, said semiconductor surface having been provided in or on the surface thereof with a contact pad, said contact pad overlying and being in electrical contact with at least one point of electrical contact in or on the surface of said substrate, said at least one point of electrical contact being created on the surface of a layer of dielectric, said layer of dielectric having been deposited over said semiconductor surface;
- and
- partially removing said contact pad, said removing having a removal thickness and removal surface area.
A method for forming a metal bump on a semiconductor surface, a layer of dielectric having been deposited over said semiconductor surface, said contact pad having been formed on the surface of said layer of dielectric, said metal bump overlying said contact pad, said contact pad having served as an Input/Output (I/O) point of contact during semiconductor device testing, said contact pad overlying and being connected to at least one point of electrical contact provided in or on the surface of said semiconductor surface, comprising the steps of:
- depositing a layer of passivation over said layer of dielectric underlying said contact pad, including the surface of said contact pad;
- patterning and etching said layer of passivation, creating an opening in said layer of passivation having a first diameter, partially exposing the surface of said contact pad over a surface area of said first diameter, said opening in said layer of passivation being centered with respect to said contact pad, said first diameter of said opening created in said layer of passivation being smaller than said surface area of said contact pad by a measurable amount;
- depositing a first layer of photoresist over the surface of said layer of passivation, including the opening created in said layer of passivation;
- patterning and etching said first layer of photoresist, creating an opening having a second diameter through said layer of photoresist, said opening in said first layer of photoresist aligning with and being centered with respect to said contact pad, said second diameter of said opening in said first layer of photoresist being smaller than said first diameter of said opening in said layer of passivation by a measurable amount;
- etching said contact pad in accordance with said opening created in said first layer of photoresist;
- removing said patterned layer of first photoresist from the surface of said layer of passivation, including the surface of said etched contact pad;
- sputtering a layer of Under Bump Metallurgy (UBM) over the surface of said layer of passivation, including exposed surface of the contact pad and exposed surface of said underlying dielectric;
- depositing a second layer of photoresist over the semiconductor surface of the layer of UBM;
- patterning and etching said second layer of photoresist, creating an opening in said second layer of photoresist that is aligned with said contact pad, partially exposing the surface of said layer of UBM;
- electroplating the partially exposed surface of said layer of UBM with a layer of bump metal, partially filling said opening created in said second layer of photoresist;
- removing said patterned and etched second layer of photoresist from above said semiconductor surface;
- and
- reflowing the surface of said layer of bump metal, forming the metal bump.
10 more elements
A metal bump on a semiconductor surface, comprising:
- a semiconductor surface, a layer of dielectric having been deposited over said semiconductor surface, a contact pad having been formed on the surface of said layer of dielectric, said metal bump overlying said contact pad, said semiconductor surface having been provided with at least one point of electrical contact, said contact pad having a surface area in addition to having a height in addition to having a surface area, said contact pad being in electrical contact with said at least one point of electrical contact;
- and
- said contact pad having been partially removed, said removing having a removal thickness and removal surface area.
A metal bump on a semiconductor surface, comprising:
- a semiconductor surface, a layer of dielectric having been deposited over said semiconductor surface, a contact pad having been formed on the surface of said layer of dielectric, said metal bump overlying said contact pad, said semiconductor surface having been provided in or on the surface thereof with at least one point of electrical contact having a height and a surface area, a contact pad having a surface area being connected with said at least one point of electrical contact having been provided on said semiconductor surface;
- a layer of passivation deposited over said layer of dielectric, including the surface of said contact pad, an opening having been created in said layer of passivation having a first diameter, partially exposing the surface of said contact pad over a surface area of said first diameter, said opening in said layer of passivation being centered with respect to said contact pad, said first diameter of said opening created in said layer of passivation having a surface area that is less than said surface area of said contact pad by a measurable amount;
- an opening created in said contact pad, partially exposing the surface of said at layer of dielectric deposited on the surface of said semiconductor surface, said opening having a second diameter, said opening created in said contact pad being centered with respect to said contact pad, said second diameter of said opening in said contact pad being smaller than said first diameter of said opening in said layer of passivation by a measurable amount;
- a layer of Under Bump Metallurgy (UBM) sputtered over the surface of said layer of passivation;
- and
- a layer of bump metal having been electroplated over the surface of said layer of UBM in an opening of a defined layer of photoresist, said opening in said layer of photoresist overlapping said opening in said passivation layer, after stripping and etching the sputtered UBM using said bump metal as a mask after which said layer of bump metal has been reflowed, forming said metal bump.
3 more elements
A method for forming a metal bump on a semiconductor surface, comprising the steps of:
- providing a semiconductor surface;
- providing a contact pad over said semiconductor surface;
- mechanically contacting a portion of said contact pad, whereby damage may occur to said portion of said contact pad;
- removing said portion of said contact pad to form an opening;
- depositing an under bump metal over said contact pad and in said opening;
- and
- forming a metal bump over said contact pad.
4 more elements
A metal bump contact, comprising;
- a semiconductor surface;
- a contact pad over said semiconductor surface, formed of a first material, and having an opening therein;
- an under bump metal formed over said contact pad and in said opening;
- and
- a metal bump formed over said contact pad.
2 more elements
Dependencies are inferred from the claim text.