WET ETCHING OF SAMARIUM SELENIUM FOR PIEZOELECTRIC PROCESSING
First Claim
1. A subtractive forming method comprising:
- providing a material stack including a samarium and selenium containing layer and an aluminum containing layer in direct contact with the samarium and selenium containing layer;
masking said material stack to expose a portion of the material stack to be etched;
patterning the aluminum containing layer;
etching the samarium component of the samarium and selenium containing layer of the exposed portion of the material stack with an etch chemistry comprising citric acid and hydrogen peroxide that is selective to the aluminum containing layer, wherein the hydrogen peroxide reacts with the aluminum containing layer to provide an oxide etch protectant surface on the aluminum containing layer, and the citric acid etches samarium selectively to the oxide etch protectant surface; and
removing a remaining selenium component of the samarium and selenium containing layer in the exposed portion of the material stack by elevating a temperature of the selenium component above a heat of vaporization for the selenium component.
1 Assignment
0 Petitions
Accused Products
Abstract
A subtractive forming method that includes providing a material stack including a samarium and selenium containing layer and an aluminum containing layer in direct contact with the samarium and selenium containing layer. The samarium component of the samarium and selenium containing layer of the exposed portion of the material stack is etched with an etch chemistry comprising citric acid and hydrogen peroxide that is selective to the aluminum containing layer. The hydrogen peroxide reacts with the aluminum containing layer to provide an oxide etch protectant surface on the aluminum containing layer, and the citric acid etches samarium selectively to the oxide etch protectant surface. Thereafter, a remaining selenium component of is removed by elevating a temperature of the selenium component.
4 Citations
10 Claims
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1. A subtractive forming method comprising:
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providing a material stack including a samarium and selenium containing layer and an aluminum containing layer in direct contact with the samarium and selenium containing layer;
masking said material stack to expose a portion of the material stack to be etched;
patterning the aluminum containing layer;etching the samarium component of the samarium and selenium containing layer of the exposed portion of the material stack with an etch chemistry comprising citric acid and hydrogen peroxide that is selective to the aluminum containing layer, wherein the hydrogen peroxide reacts with the aluminum containing layer to provide an oxide etch protectant surface on the aluminum containing layer, and the citric acid etches samarium selectively to the oxide etch protectant surface; and removing a remaining selenium component of the samarium and selenium containing layer in the exposed portion of the material stack by elevating a temperature of the selenium component above a heat of vaporization for the selenium component. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10-20. -20. (canceled)
Specification