**5. Conclusions**

This study reports methods to fabricate Al0.68Sc0.32N films and cantilevers with low average stress and with low through-thickness stress gradients. Al1−xScxN films were optimized to control stress for N<sup>2</sup> flows between 20 to 30 sccm. The average stress within the films ranged from 78.6 MPa to 349.6 MPa. The out-of-plane tip deflection for 100 µm long cantilevers fabricated in 500 nm thick Al0.68Sc0.32N films was reduced from >109 µm for films without stress gradient compensation to less than 3 µm and 8 µm for 2- and 5-layer compensated film stacks for dies studied in the wafer center. The resulting deposition parameters provide methods to control stress and through-thickness stress gradients in highly Sc alloyed AlN materials and are promising for next-generation MEMS devices.

**Author Contributions:** Conceptualization, R.B. and R.H.O.III; methodology, R.B.; validation, R.B., K.K. and M.D; formal analysis, R.B., K.K. and M.D; investigation, R.B. and K.K.; resources, R.H.O.III; data curation, R.B., K.K. and M.D.; writing—original draft preparation, R.B.; writing—review and editing, R.B., M.D. and R.H.O.III; visualization, R.B.; supervision, R.H.O.III; project administration, R.H.O.III; funding acquisition, R.H.O.III. All authors have read and agreed to the published version of the manuscript.

**Funding:** This work was funded in part by the NSF CAREER Award (1944248) and in part The Defense Advanced Research Projects Agency (DARPA) Small Business Innovation Research (SBIR) under award HR0011-21-9-0004. This work was carried out in part at the Singh Center for Nanotechnology at the University of Pennsylvania, a member of the National Nanotechnology Coordinated Infrastructure (NNCI) network, which is supported by the National Science Foundation (Grant No. HR0011-21-9-0004). This research was, in part, funded by the U.S. Government. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, of the U.S. Government.

**Data Availability Statement:** The data that support the findings of this study are available from the corresponding author upon reasonable request.

**Conflicts of Interest:** The authors declare no conflict of interest.
