US 11,929,257 B2
Etching solution and method for aluminum nitride
Chung Yi Chang, New Taipei (TW); Wen Dar Liu, Zhubei (TW); and Yi-Chia Lee, Hsinchu (TW)
Assigned to Versum Materials US, LLC, Tempe, AZ (US)
Appl. No. 17/622,670
Filed by VERSUM MATERIALS US, LLC, Tempe, AZ (US)
PCT Filed Mar. 10, 2020, PCT No. PCT/US2020/021837
§ 371(c)(1), (2) Date Dec. 23, 2021,
PCT Pub. No. WO2020/185745, PCT Pub. Date Sep. 17, 2020.
Claims priority of provisional application 62/894,759, filed on Aug. 31, 2019.
Claims priority of provisional application 62/816,781, filed on Mar. 11, 2019.
Prior Publication US 2022/0367199 A1, Nov. 17, 2022
Int. Cl. H01L 21/306 (2006.01); C09K 13/06 (2006.01)
CPC H01L 21/30617 (2013.01) [C09K 13/06 (2013.01)] 21 Claims
 
1. An etching solution suitable for at least partially removing aluminum nitride from a microelectronic device during manufacture of the device, the solution comprising:
water;
a cationic surfactant having a structure represented by Formula A:

OG Complex Work Unit Chemistry
wherein, each of R1, R2, R3, and R4 is independently hydrogen, a substituted or unsubstituted C1-C30 alkyl, a substituted or unsubstituted C3-C8 cycloalkyl, a substituted or unsubstituted C2-C30 alkenyl, a substituted or unsubstituted aralkyl, a substituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl, wherein not all of R1, R2, R3, and R4 are hydrogen; and
X is an anionic counterion;
a water-miscible organic solvent; and
greater than 10% by weight of base comprising potassium hydroxide,
wherein the etching solution is free of solid materials, fluoride, oxidizers, peroxides, inorganic acids, and organic acids.