Patent ID: 9627561
Date: 2017-04-18
CPC Classifications: H01L,Y02E,Y02P

Claim:
1. A method comprising the steps of: providing a wafer comprising a substrate and three or more subcells of a multijunction solar cell overlying the substrate, wherein, patterning the wafer with a mesa etch pattern using photolithography; and etching in exposed areas the three or more subcells and part or all of the substrate according to the mesa etch pattern using a single nonselective etchant mixture comprising hydrochloric acid, iodic acid, and water, for yielding mesa isolation of individual multijunction solar cells characterized by a macroscopically smooth substantially inwardly curved sidewall profile, wherein the etchant mixture comprises a molar ratio of 0.95 moles to 1.05 moles iodic acid:59 moles to 65 moles hydrochloric acid:760 moles water.