US 12,237,647 B2
Techniques for vertical cavity surface emitting laser oxidation
Chen Yu Chen, Hsinchu (TW); Ming Chyi Liu, Hsinchu (TW); and Jhih-Bin Chen, Hsinchu (TW)
Assigned to Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Company, Ltd., Hsin-Chu (TW)
Filed on Apr. 12, 2022, as Appl. No. 17/718,393.
Application 17/718,393 is a division of application No. 17/070,508, filed on Oct. 14, 2020, granted, now 11,309,685.
Application 17/070,508 is a continuation of application No. 16/122,018, filed on Sep. 5, 2018, granted, now 10,847,949, issued on Nov. 24, 2020.
Claims priority of provisional application 62/724,243, filed on Aug. 29, 2018.
Prior Publication US 2022/0239067 A1, Jul. 28, 2022
Int. Cl. H01S 5/183 (2006.01); H01S 5/02 (2006.01); H01S 5/028 (2006.01); H01S 5/187 (2006.01); H01S 5/20 (2006.01)
CPC H01S 5/18358 (2013.01) [H01S 5/021 (2013.01); H01S 5/028 (2013.01); H01S 5/18308 (2013.01); H01S 5/18311 (2013.01); H01S 5/18322 (2013.01); H01S 5/187 (2013.01); H01S 5/2027 (2013.01); H01S 5/2086 (2013.01)] 20 Claims
OG exemplary drawing
 
16. A method for forming a vertical cavity surface emitting laser (VCSEL) structure comprising:
forming an optically active layer over a lower reflective layer;
forming an upper reflective layer over the optically active layer;
forming a masking layer over the upper reflective layer, wherein the masking layer covers a reflector region of the upper reflective layer, wherein the masking layer leaves a sacrificial portion of the upper reflective layer exposed;
performing a first etch process to remove the sacrificial portion of the upper reflective layer, defining an upper reflector and exposing an upper surface of the optically active layer;
forming a first spacer covering outer sidewalls of the upper reflector and outer sidewalls of the masking layer, wherein a lower surface of the first spacer contacts the upper surface of the optically active layer;
performing an oxidation process with the first spacer in place to oxidize a peripheral region of the optically active layer while leaving a central region of the optically active layer un-oxidized;
performing a second etch process to remove a portion of the oxidized peripheral region, defining an optically active region and removing a portion of the lower reflective layer, defining a lower reflector; and
forming a second spacer covering outer sidewalls of the first spacer, outer sidewalls of a remaining portion of the oxidized peripheral region, and outer sidewalls of the lower reflector.