The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 09, 2024
Filed:
Aug. 02, 2021
National Technology & Engineering Solutions of Sandia, Llc, Albuquerque, NM (US);
Giovanni Esteves, Albuquerque, NM (US);
Travis Ryan Young, Albuquerque, NM (US);
National Technology & Engineering Solutions of Sandia, LLC, Albuquerque, NM (US);
Abstract
An aluminum-scandium (Al—Sc) etch stop that is both CMOS compatible and highly conductive, and a method for forming the same are disclosed. The low volatility of Sc in Cl and strong covalent bond between Al—Sc leads to an increase in resistance to NaCl corrosion and makes it difficult to dry etch in Cl-based chemistries, resulting in an excellent etch stop material, especially when used in conjunction with an overlying aluminum nitride (AlN) or aluminum scandium nitride (AlScN) piezoelectric layer. When deposited at high deposition temperatures or when subsequently annealed at >600° C., the Al—Sc has a low resistivity, enabling corresponding device operation at temperatures up to at least 500° C. While AlSc is the preferred composition, AlScwith x between 5 and 100 atomic percent provides many of these same benefits but comes at the cost of increased electrical resistivity and etch resistance with increasing Sc content due to Sc oxidation.