A Reproducible, High Yield, Robust Wet Etch Etch-Stop Process Using Organic Acid – Peroxide Solutions
Frank Spooner, William Quinn, Larry Hanes, Sarah Woolsey, Kim Smith, Jerry Mason
Skyworks Solutions, Inc.,
Phone: 781.376.3193, e-mail: firstname.lastname@example.org
Keywords: uniformity, stability, selectivity, etch pits, GaAs, p-HEMT
Continuous improvement has been key to the successful wet etch etch-stop process at Skyworks Solutions. Three conditions: device dimensions, etch chemistry, and etch tool directly affected the etched depth uniformity across a wafer. An unusual failure mechanism of the etch stop process was discovered while investigating a range of over etched devices. This failure mechanism was a perforation mode which standard profilometry would not reveal. The paper will show how the etch uniformity and yield is impacted by device geometry, etch chemistry, etch tool and surface pitting.