Semiconductor device manufacturing: process – Chemical etching – Vapor phase etching
Reexamination Certificate
1998-11-30
2001-10-02
Utech, Benjamin L. (Department: 1765)
Semiconductor device manufacturing: process
Chemical etching
Vapor phase etching
C438S720000, C438S723000
Reexamination Certificate
active
06297164
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a method for producing contact structures, and more particularly, to a method for producing a large number of contact structures on a semiconductor wafer in a horizonal direction and removing the contact structures from the wafer to be mounted on a probe card, IC chip, or other contact mechanism in a vertical direction.
BACKGROUND OF THE INVENTION
In testing high density and high speed electrical devices such as LSI and VLSI circuits, a high performance probe card having a large number of contact structures must be used. In other application, contact structures may be used for IC packages as IC leads. The present invention is directed to a production process of such contact structures to be used in testing LSI and VLSI chips, semiconductor wafers, burn-in of semiconductor wafers and die, testing and burn-in of packaged semiconductor devices, printed circuit boards and the like, as well as used in forming leads of IC chips or IC packages.
The inventors of this application have proposed a new type of contact structure to be used in such applications noted above in U.S. patent application Ser. No. 09/099,614 filed Jun. 19, 1998, entitled “Probe Contactor Formed by Photolithography Process”, U.S. patent application Ser. No. 09/140,961 filed Aug. 27, 1998, entitled “High Performance Integrated Circuit Chip Package”, and U.S. patent application Ser. No. 09/157,842 filed Sept. 21, 1998, entitled “Packaging and Interconnection of Contact Structure”. This invention is directed to a method of producing the contact structures shown in such patent applications.
In the above noted patent applications, the inventors have proposed a unique type of contact structures as shown in FIG.
1
. The example of
FIG. 1
shows the application in which contact structures
30
are mounted on a contact substrate such as a probe card to electrically contact the targets such as contact pads
320
on a printed circuit board
300
. The contact structures
30
are formed through a photolithography process on a semiconductor substrate
20
, which is fully described in the above patent applications.
Although the production methods introduced in the above noted patent applications appear to be successful, the methods require relatively many lithography steps to form the structure in a vertical direction on the substrate. The inventors have attained a more simplified and low cost production process which is also able to achieve contact structures of higher reliability because of the simplified production process.
SUMMARY OF THE INVENTION
Therefore, it is an object of the present invention to provide a method for producing a large number of contact structures by using relatively simple technique.
It is another object of the present invention to provide a method for producing a large number of contact structures in a two dimensional manner rather than a three dimensional manner on a planar surface of a silicon substrate.
It is a further object of the present invention to provide a method for producing a large number of contact structures in a two dimensional manner on a silicon substrate, removing the contact structures from the substrate to be mounted on a probe card or other contact mechanism in a three dimensional manner.
It is a further object of the present invention to provide a method for producing a large number of contact structures with low cost and high efficiency.
It is a further object of the present invention to provide a method for producing a large number of contact structures of high mechanical strength and reliability.
It is a further object of the present invention to provide a method of producing contact structures to be used in testing and burn-in semiconductor wafers, packaged LSIs and the like.
In the present invention, contact structures for testing (including burn-in) a semiconductor wafers, packaged LSIs or printed circuit boards (devices under test) are formed on a planar surface of a silicon substrate by a photolithography technology established in the semiconductor production process.
The production method of the present invention is comprised of the steps of:
(a) forming a sacrificial layer on a surface of a silicon substrate;
(b) forming an conductive layer made of electric conductive material on the sacrificial layer;
(c) forming a photoresist layer on the conductive layer;
(d) aligning a photo mask over the photoresist layer and exposing the photoresist layer with ultraviolet light through the photo mask, the photo mask including an image of the contact structures;
(e) developing the image on the photoresist layer which has openings on the surface of the photoresist layer;
(f) forming the contact structures made of electric conductive material in the openings by an electroplating process;
(g) stripping the photoresist layer;
(h) removing the sacrificial layer by a first etching process so that the contact structures are separated from the silicon substrate; and
(i) removing the conductive layer from the contact structure by a second etching process.
Another aspect of the present invention is a process of producing a contact mechanism having contact structures each of which is able to exhibit a spring force for establishing electrical contact with a contact target. The production process is comprised of the following steps of:
(a) forming a sacrificial layer on a surface of a silicon substrate;
(b) forming an conductive layer made of electric conductive material on the sacrificial layer;
(c) forming the contact structures through a photolithography process, the contact structures being in a horizontal directions on the silicon substrate;
(d) removing the contact structures from the silicon substrate and from the conductive layer;
(e) aligning and orienting the contact structures in a predetermined direction;
(f) positioning the contact mechanism having bonding locations for mounting the contact structures thereon; and
(g) picking at least one of the contact structures and placing the same on a predetermined position on a bonding pad of the contact mechanism and bonding the contact structure to the bonding pad.
REFERENCES:
patent: 4604160 (1986-08-01), Murakami et al.
patent: 4705592 (1987-11-01), Bahrle et al.
patent: 5028513 (1991-07-01), Murakami et al.
patent: 5286335 (1994-02-01), Drabik et al.
patent: 5465009 (1995-11-01), Drabik et al.
patent: 5486483 (1996-01-01), Lammert
patent: 5527766 (1996-06-01), Eddy
patent: 5538922 (1996-07-01), Cooper et al.
patent: 5607818 (1997-03-01), Akram et al.
Frame James W.
Jones Mark R.
Khoury Theodore A.
Advantest Corp.
Muramatsu & Associates
Tran Binh X
Utech Benjamin L.
LandOfFree
Method for producing contact structures does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for producing contact structures, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for producing contact structures will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2572080