Semiconductor device manufacturing: process – Chemical etching – Altering etchability of substrate region by compositional or...
Reexamination Certificate
2002-11-15
2009-06-09
Goudreau, George A. (Department: 1792)
Semiconductor device manufacturing: process
Chemical etching
Altering etchability of substrate region by compositional or...
C438S719000, C438S742000, C438S753000, C216S062000, C216S074000, C216S087000, C134S001300
Reexamination Certificate
active
07544622
ABSTRACT:
A contact is defined by an opening etched into borophosphosilicate glass (BPSG) down to a silicon substrate. In a contact cleaning process designed to remove native oxide at the bottom of the contact with little effect on the BPSG, the contact is dipped in an etch retardant before being dipped in a cleaning solution containing both the etch retardant and an etchant. The dip in etch retardant modifies the surface of the BPSG, thereby lessening the enhanced etching experienced during the initiation of the dip into the etchant/etch retardant cleaning solution. Results of a etchant/etch retardant clean, both with and without the prepassivation, can be illustrated on a graph depicting the change in contact diameter as a function of dip time. Specifically, the results define “best fit” lines on that graph. For a given dip time, a first line representing the prepassivation+etchant/etch retardant clean is 30 to 40 Angstroms lower than a second line representing the prior art clean using the etchant/etch retardant without prepassivation. Accordingly, the first line's Y-axis intercept, representing the “zero dip time,” is also 30 to 40 Angstroms lower than the second line's zero dip time.
REFERENCES:
patent: 3837945 (1974-09-01), Chiang
patent: 4230523 (1980-10-01), Gajda
patent: 4298402 (1981-11-01), Hingarh
patent: 4343677 (1982-08-01), Kinsbron et al.
patent: 4595519 (1986-06-01), Takeno et al.
patent: 4785337 (1988-11-01), Kenney
patent: 4871422 (1989-10-01), Scardera et al.
patent: 4879457 (1989-11-01), Ludden
patent: 4899767 (1990-02-01), McConnell et al.
patent: 4921572 (1990-05-01), Roche
patent: 4992134 (1991-02-01), Gupta et al.
patent: 5039349 (1991-08-01), Schoeppel
patent: 5112437 (1992-05-01), Watanabe et al.
patent: 5277835 (1994-01-01), Ohmi et al.
patent: 5571447 (1996-11-01), Ward et al.
patent: 5698503 (1997-12-01), Ward et al.
patent: 5783495 (1998-07-01), Li et al.
patent: 5855811 (1999-01-01), Grieger et al.
patent: 5990019 (1999-11-01), Torek et al.
patent: 6012469 (2000-01-01), Li et al.
patent: 6063712 (2000-05-01), Gilton et al.
patent: 6235145 (2001-05-01), Li et al.
patent: 6238592 (2001-05-01), Hardy et al.
patent: 6280651 (2001-08-01), Wojtczak et al.
patent: 6358788 (2002-03-01), Chen et al.
patent: 6489248 (2002-12-01), Zhang et al.
patent: 6562726 (2003-05-01), Torek et al.
patent: 6740595 (2004-05-01), Kudelka et al.
patent: 6743722 (2004-06-01), Kassir
patent: 2001/0051440 (2001-12-01), Torek et al.
patent: 2005/0104114 (2005-05-01), Chen et al.
patent: 2006/0289389 (2006-12-01), Shea
patent: 2007/0163997 (2007-07-01), Shea
patent: 2007/0178705 (2007-08-01), Shea
patent: 52-21457 (1977-06-01), None
patent: 09-022881 (1997-01-01), None
“Fabrication of Novel Three-Dimensional Microstructures by the Anisotropic Etching of (100) and (110) Silicon”; IEEE Transactions of Electron Devices; 1978; vol. ED25; No. 10, pp. 1178-1185; Bassous.
Wolf, S.,Silicon Processing for the VLSI Era, (1), Process Technology,(1986),514-517 and 551-552.
Wolf, S.,Silicon Processing for the VLSI Era, Lattice press(1), (1986), 514-519.
Blain, M. G., et al., “Chemical downstream etching of tungsten”,J. of Vacuum Science, A, 16(4), (1998), 2115-2119.
Goudreau George A.
Micro)n Technology, Inc.
Schwegman Lundberg & Woessner, P.A.
LandOfFree
Passivation for cleaning a material does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Passivation for cleaning a material, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Passivation for cleaning a material will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-4121617