METAL BODY HAVING MAGNESIUM FLUORIDE REGION FORMED THEREFROM
Described are metal bodies made of magnesium-containing metal and having a magnesium fluoride surface passivation region formed at a surface of the body, as well as methods of forming a magnesium fluoride surface passivation region at a surface of a metal body, and uses for the bodies.
1 . An article including comprising:
a semiconductor processing device component having a metal body including
a bulk region comprising a metal alloy including magnesium,
a surface passivation region comprising magnesium fluoride at a surface of the metal body, and
a transition region between the bulk region and the surface passivation region having a ratio of magnesium fluoride to metal alloy that gradually increases in a direction from the bulk region to the surface passivation region.
2 . The article of claim 1 , wherein there is no discrete boundary between the bulk region, the transition region and the surface passivation region at the surface of the metal body.
3 . The article of claim 1 , wherein the metal alloy comprises at least 0.5 weight percent magnesium.
4 . The article of claim 1 , wherein the metal alloy includes at least 93 weight percent aluminum, magnesium, and at least 0.5 weight percent non-magnesium impurities.
5 . The article of claim 1 , wherein the metal alloy is an aluminum alloy and comprises:
from 95 to 99 weight percent aluminum;
from 0.8 to 1.2 weight percent magnesium;
from 0.4 to 0.8 weight percent silicon;
not more than 0.7 weight percent iron;
from 0.15 to 0.4 weight percent copper; and
from 0.04 to 0.35 weight percent chromium.
6 . The article of claim 1 , wherein a thickness of the surface passivation region ranges from 1 to 200 nm, the thickness of the surface passivation region being measured from the surface of the metal body to a point within the transition region of the metal body wherein a ratio of the magnesium fluoride to metal alloy is about 50:50.
7 . The article of claim 1 , wherein the magnesium fluoride is polycrystalline and has the crystal structure of MgF 2 as measured by X-ray powder diffraction (XRD).
8 . The article of claim 1 , wherein the surface of the metal body comprises high aspect ratio features having an aspect ratio ranging from 20:1 to 500:1 and wherein the surface passivation region is formed such that it has a uniform thickness on the high aspect ratio features.
9 . The article of claim 8 , wherein the metal body is any one of an opening, an aperture, a channel, a tunnel, a threaded screw, a threaded nut, a porous membrane, a filter, or a three-dimensional network.
10 . The article of claim 8 , wherein the metal body is a three-dimensional network.
11 . The article of claim 8 , wherein the metal body is a porous membrane.
12 . The article of claim 1 , wherein the metal alloy contains less than 5 weight percent of all combined non-magnesium elements.
13 . The article of claim 1 , wherein the surface passivation region is resistant to thermal degradation by temperatures up to and including 500 degrees Celsius.
14 . The article of claim 1 , wherein the surface passivation region has an etch rate of less than 1 μm/hour when subjected to reactive ion etching (RIE-F).