Oxford ICP Etcher - Process Control Data

Data - InP Ridge Etch (Oxford ICP Etcher)

PECVD SiO2 hardmask, patterned on Stepper #2 (AutoStep 200) & Panasonic ICP #1

InP Ridge Etch: 60°C, 3mT, 800W/65W, Cl2=18, H2=15, CH4=10sccm, time=5min00sec (300sec) Sample Size: 1x1cm, ~30-40% SiO2 masking (NingC's pattern). Silicon carrier, no adhesive.
Date	Sample#	Etch Rate (nm/min)	Etch Selectivity (InP/SiO2)	Comments	SEM Images
4/27/22				directly after chamber clean
4/26/22	NP_60c_007	312	9.93	day before chamber clean	[1] [2]
4/19/22	NP_60c_006	330	9.53	brown gunk found in chamber right after the etch was done--may be cause of lower etch rates recently	[1] [2]
4/13/22	NP_60c_005	320	11.51		[1] [2]
3/30/22	NP_60c_004	427	11.17	*etched for 3min*	[1][2]
1/26/22	NP_1_26_003	452	12.9	~30-40% SiO2 masking (NingC's pattern)	[1] [2]
1/26/22	NP_1_26_001	~400nm	~7	~30-40% SiO2 masking (NingC's pattern)	[1] [2]

Dependence on Sample Size

We have found that the size of the InP piece loaded (no adhesive, onto Silicon carrier wafer) affects the etch rate, but does not affect the etch profile - ie. etches are still smooth and vertical, but rate varies with sample area.

InP Ridge Etch: 60°C, 3mT, 800W/65W, Cl2=18, H2=15, CH4=10sccm, time=5min05sec (305sec) Silicon carrier, no adhesive.
Date	Sample#	Sample Size (dimensions, mm)	Sample Size (area, mm2)	Etch Rate (nm/min)	Etch Selectivity (InP/SiO2)	Comments	SEM Images
1/11/22	DJ_InPRidge	4.5 x 2.5	11.25	602	64.6nm left	~50% SiO2 masking (GCA Calibration pattern)	[1]
1/12/22	DJ_InPRidge	4.5 x 3	13.5	563	76.4nm left	~50% SiO2 masking (GCA Calibration pattern)	[2]
1/12/22	DJ_InP#3	4.5 x 3	13.5	612	71nm left	~50% SiO2 masking (GCA Calibration pattern)	[3]
1/26/22	NP_?	10 x 10	100	400-450	~250nm left	~30-40% SiO2 masking (NingC's pattern)
1/26/22	NP_?	1/4 of 50mm wafer	490	378	276nm left	~30-40% SiO2 masking (NingC's pattern)	[1]