High speed, low driving voltage vertical cavity germanium-silicon modulators for optical

Appendix A 
The description below is the full description of the SiGe multiple quantum well 
structure. 
Operating pressure: 40 Torr Carrier gas flow: hydrogen 12.5 slm 
Step 001: 1000ºC oxide blow-off bake for 5 minutes 
Step 002: Cool down to 740ºC and stabilize the temperature and gas source for 60 
seconds 
Step 003: SiH
2
Cl
2
flow 100 and deposit Si for 120 seconds 
Step 004: Cool down to 395ºC for Si
0.1
Ge
0.9
alloy growth 
Step 005: GeH
4
flow 40 sccm, SiH
4
flow 35.8 sccm, 100ppm B
2
H
6
mixed dopant flow 
of 100 sccm with mixed ratio of 50%. Growth temperature 395ºC. Grow 200 nm of 
p-doped Si
0.1
Ge
0.9
alloy for 25 minutes 
Step 006: Temperature ramp up to 850ºC and anneal for 30 minutes 
Step 007: GeH
4
flow 40 sccm, SiH
4
flow 35.8 sccm, 100ppm B
2
H
6
mixed dopant flow 
of 100 sccm with mixed ratio of 50%. Growth temperature 395ºC. Grow 200 nm of 
p-doped Si
0.1
Ge
0.9
alloy for 25 minutes
Step 008: Temperature ramp up to 750ºC and anneal for 30 minutes 
Step 009: Purge all gases for 5 minutes 
Step 010: GeH
4
flow 40 sccm, SiH
4
flow 35.8 sccm, Growth temperature 395ºC. 
Grow 100 nm of intrinsic Si
0.1
Ge
0.9
alloy for 12.5 minutes
Step 011: GeH
4
flow 40 sccm, SiH
4
flow 60 sccm, Growth temperature 395ºC. Grow 
16 nm of intrinsic Si
0.15
Ge
0.85
alloy for 243 seconds 
Step 012: GeH
4
flow 40 sccm, Growth temperature 395ºC. Grow 16 nm of intrinsic 
Ge alloy for 49 seconds 

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89 
Repeat step 011-012 for 10 times to grow 10 pairs of quantum wells. 
Step 013: GeH
4
flow 40 sccm, SiH
4
flow 35.8 sccm, Growth temperature 395ºC. 
Grow 100 nm of intrinsic Si
0.1
Ge
0.9
alloy for 12.5 minutes
Step 014: GeH
4
flow 40 sccm, SiH
4
flow 35.8 sccm, 100ppm AsH
3
mixed dopant flow 
of 100 sccm with mixed ratio of 50%. Growth temperature 375ºC. Grow 200 nm of 
p-doped Si
0.1
Ge
0.9
alloy for 25 minutes

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90