Test Data of etching SiO2 with CHF3/CF4

ICP#2: 0.5Pa, 50/900W, CHF3/CF4=10/30 sccm, time=210 sec
Date	Sample#	Etch Rate (nm/min)	Etch Selectivity (SiO2/PR)	Averaged Sidewall Angle (o)	SEM Images
10/5/2018	SiO2#02	160	1.2	82.1	[1]
1/28/2019	I21901	146	1.23		[2]
3/6/2019	I21904	151	1.23	85.6	[3]
7/18/2019	I21905	162	1.37		[4]
1/16/2020	I22001	149	1.21		[5]
8/9/2020	I22002	102	0.86	caused by air leaking to CHF3 channel	[6]
1/7/2021	I22101	144	1.20		[7]
5/19/2021	I22102	163	1.11	Etch time=130 sec	[8]
7/21/2021	I22103	134	1.09	Investigating reports of low etch rate	[9]
8/9/2021	I22104	147	1.06	Before etching diamond sample for 1 hour using Cl2/Ar	[10]
8/9/2021	I22105	140	0.97	After etching diamond sample for 1 hour using Cl2/Ar	[11]