US 12,334,353 B2
Method and apparatus for plasma etching
Weikang Fan, Newport (GB); and Stephan Shannon L. Lilje, Newport (GB)
Assigned to SPTS Technologies Limited, Newport (GB)
Filed by SPTS Technologies Limited, Newport (GB)
Filed on Oct. 26, 2021, as Appl. No. 17/511,478.
Claims priority of application No. 2020822 (GB), filed on Dec. 31, 2020.
Prior Publication US 2022/0208550 A1, Jun. 30, 2022
Int. Cl. H01L 21/306 (2006.01); H01J 37/32 (2006.01); H01L 21/3065 (2006.01)
CPC H01L 21/3065 (2013.01) [H01J 37/32266 (2013.01); H01J 37/32146 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A method of plasma etching a compound semiconductor substrate, the method comprising the steps of:
providing a substrate on a substrate support within a chamber, wherein the substrate comprises a compound semiconductor material that includes a IV-IV, III-V or II-VI compound semiconductor;
introducing an etchant gas or gas mixture into the chamber, wherein the etchant gas or gas mixture comprises a chlorine-containing chemical etchant gas;
sustaining a plasma of the etchant gas or gas mixture within the chamber to plasma etch the compound semiconductor material, wherein the plasma is an inductively coupled plasma; and
applying a pulsed electrical bias power to the substrate support whilst the plasma of the etchant gas or gas mixture is being sustained;
wherein the pulsed electrical bias power has a pulse frequency of less than or equal to about 160 Hz and a duty cycle of less than or equal to about 50%.