Electricity: measuring and testing – Fault detecting in electric circuits and of electric components – Of individual circuit component or element
Reexamination Certificate
2001-07-12
2002-07-16
Warden, Jill (Department: 1743)
Electricity: measuring and testing
Fault detecting in electric circuits and of electric components
Of individual circuit component or element
C422S088000, C117S098000, C205S775000
Reexamination Certificate
active
06420893
ABSTRACT:
TECHNICAL FIELD
The present invention generally relates to methods for measuring contaminant mobile ions in dielectric materials. More particularly, the present invention relates to methods for measuring contaminant mobile ions in a dielectric portion of a semiconductor.
BACKGROUND OF THE INVENTION
Generally, semiconductor devices are formed by patterning substantially coplanar conductive traces or interconnects onto the surfaces of substrates followed by layering of the substrates. The substrates are typically formed of dielectric materials or include portions of dielectric material (e.g., dielectric layers or films). The portions of dielectric material (i.e., dielectric portions) are included on the substrates to electrically separate interconnects of the layered substrates and exemplary dielectric materials used for semiconductor devices include, but are not limited to, silicon dioxide (oxide) and silicon nitride.
Due to processing of the substrates and other conditions, the dielectric portions often contain variable levels of electrically charged contaminant mobile ions. Such electrically charged ions within the dielectric portions of the substrates can reduce reliability in semiconductor devices such as metal oxide semiconductor (MOS) devices. As an example, ionized alkali metal atoms (e.g., Na
+
and K
+
) are mobile in oxide layers, and move through gate oxides of MOS devices under the influence of the electric fields generated between gate electrodes and substrates during MOS operation. Over time, mobile ions in gate oxides can drift toward interfaces between the gate oxides and underlying substrates and the resulting changes in MOS device threshold voltage levels may become significant enough to cause electrical performance degradation in circuits that incorporate the MOS device.
To assist in maintaining low levels of mobile ion contamination, it is desirable to measure the contamination. Capacitance/Voltage (C/V) methods, bias temperature treatment methods and other similar methods are commonly employed to monitor such contamination by inducing drift or mobilization of mobile ions within the dielectric materials and measuring differences in electric potential or voltage caused by the mobile ions. Examples of such methods are discussed in commonly owned U.S. Pat. No. 5,963,783, issued to Lowell et al on Oct. 5, 1999, which is herein fully incorporated by reference. These methods commonly employed to measure contamination can be improved if the differences in electric potential upon which contamination measurements may be based take into account non-contaminant mobilized ions or charges and/or contaminant mobile ions that generally remained immobilized during previous methods employed to conduct contamination measurements.
In view of the foregoing, it is desirable to provide methods for measuring contaminant mobile ions in dielectric materials. In addition, it is desirable to provide methods for measuring contaminant mobile ions in a dielectric portion of a semiconductor. Furthermore, additional desirable features will become apparent to one of ordinary skill in the art from the drawings, foregoing background of the invention and following detailed description of the drawings, and appended claims.
SUMMARY OF THE INVENTION
In accordance with the present invention, a method is provided for measuring contaminant mobile ions in a dielectric portion of a semiconductor. The method is comprised of elevating a temperature of the dielectric portion of the semiconductor and exposing the dielectric portion of the semiconductor to a mobilizing fluid having contaminant releasing atoms after elevating the temperature of the dielectric portion, thereby assisting in mobilizing the contaminant mobile ions within the dielectric portion of the semiconductor. The method is further comprised of measuring contaminant mobile ions within the dielectric portion of the semiconductor after elevating the temperature of the dielectric portion and exposing the dielectric portion to the mobilizing fluid.
REFERENCES:
patent: 4978915 (1990-12-01), Andrews, Jr. et al.
patent: 4980301 (1990-12-01), Harrus et al.
patent: 5275687 (1994-01-01), Choquette et al.
patent: 5519334 (1996-05-01), Dawson
patent: 5773989 (1998-06-01), Edelman et al.
patent: 5804981 (1998-09-01), Lowell et al.
patent: 5963783 (1999-10-01), Lowell et al.
patent: 6011404 (2000-01-01), Ma et al.
patent: 6073501 (2000-06-01), Rohner
Wolf, Stanley Ph.D. and Richard N. Tauber, Ph.D, “Silicon Processing for the VLSI Era”, 1986, pp. 220-228, vol. 1: Process Technology, Lattice Press, Sunset Beach, California.
Garcia James
McBride Michael
Ingrassia Fisher & Lorenz
Sines Brian
Warden Jill
LandOfFree
Methods for measuring contaminant mobile ions in dielectric... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Methods for measuring contaminant mobile ions in dielectric..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Methods for measuring contaminant mobile ions in dielectric... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2843593