1. Structures of InP Epitaxy Wafer
Structure1: 1.55um InGaAsP QW laser
| No. | Layer | Doping |
| 0 | InP Substrate | S-doped, 2E18/cm-3 |
| 1 | n-InP buffer | 1.0um, 2E18/cm-3 |
| 2 | 1.15Q-InGaAsP waveguide | 80nm,undoped |
| 3 | 1.24Q-InGaAsP waveguide | 70nm,undoped |
| 4 | 4×InGaAsP QW（+1%） 5×InGaAsP Barrier |
5nm 10nm PL:1550nm |
| 5 | 1.24Q-InGaAsP waveguide | 70nm,undoped |
| 6 | 1.15Q-InGaAsP waveguide | 80nm,undoped |
| 7 | InP space layer | 20nm,undoped |
| 8 | InP | 100nm,5E17 |
| 9 | InP | 1200 nm, 1.5E18 |
| 10 | InGaAs | 100 nm, 2E19 |
Specification of Structure1:
1) Method: MOCVD
2) Size of wafer: 2”
3) InGaAsP/InGaAs growth on InP substrates
4) 3-5 types of InGaAsP composition
5) PL tolerance of +/- 5nm, PL std. dev. <3nm across the wafer (with an exclusion zone of 5mm from the wafer circumference)
6) PL target range 1500nm.
7) Strain target -1.0% +/- 0.1% (compressive strain)
8) No. of layers: 8-20
9) Total growth thickness: 1.0~3.0um
10) Parameters to be measured: X-Ray Diffraction Measurement (thickness, strain), Photoluminescence Spectrum (PL, PL uniformity), Carrier Concentration Profiling
Structure 2：InP-based Wafers for Fabricating Photodiodes
PAM-201113-INP-BASED
Specification for MUTC-PD Layer Structure
| No. | Material | Doping concentration
(cm-3) |
Thickness
(um) |
| 15 | p+-InGaAs:Zn | – | 0.05 |
| 14 | p+-InP:Zn | – | – |
| 13 | p+-InGaAsP:Zn(Q1.10 um) | – | 0.01 |
| 12 | p+-InGaAsP:Zn(Q1.40 um) | 2×1018 | – |
| 11 | p+-InGaAs:Zn | – | 0.05 |
| 10 | p-InGaAs:Zn | – | – |
| 9 | p+-InGaAs:Zn | – | – |
| 8 | n-InGaAs:Si | – | – |
| 7 | n-InGaAsP:Si(Q1.50 um) | 1×1016 | – |
| 6 | n-InGaAsP:Si(Q1.15 um) | – | 0.01 |
| 5 | n+-InP:Si | – | – |
| 4 | n-InP:Si | 5×1016 | – |
| 3 | n-InP:Si | – | 0.10 |
| 2 | n+-InGaAsP.Si(Q1.25 um) | – | – |
| 1 | n+-InP:Si | – | |
| 0 | S.I. InP-substrate (2″ wafer) | Fe-Doped | – |
Structure 3:
PAM-190925-INGAASP
Substrate: 3″, InP:S[100], Nc = (3-8)E18/cc, EPD < 5000/cm2
Epi-layer 1: 300nm InP, undoped
Epi-layer 2: 200nm, InGaAsP, undoped, lattice matched, emitting at 1275 nm
Epi-layer 3: 100nm, InP, undoped
Structure 4:
Substrate: 3″, InP:S[100], Nc = (3-8)E18/cc, EPD < 5000/cm2
Epi-layer 1: 300nm InP, undoped
Epi-layer 2: 75nm, InGaAsP, undoped, lattice matched, emitting at 1000 nm
Epi-layer 3: 50nm, InGaAsP, undoped, lattice matched, emitting at 1275 nm
Epi-layer 4: 75nm, InGaAsP, undoped, lattice matched, emitting at 1000 nm
Epi-layer 5: 100nm, InP, undoped
Structure 5:
P-type InP thin films on undoped InP substrate (DSP)
PAM181011-INP
| Layer No. | Composition | Thickness |
| Epi-layer 5 | p-InP | 50nm |
| Epi-layer 4 | InGaAsP undoped | – |
| Epi-layer 3 | p-InP | 50nm |
| Epi-layer 2 | InGaAsP undoped | – |
| Epi-layer 1 | p-InP | – |
| Substrate | InP | – |
We compare the photocarrier lifetime measured in Br-irradiated InGaAs and cold Fe-implanted InGaAsP. We also demonstrate the possibility of a two-photon absorption (TPA) process in ErAs:GaAs. The lifetime and the TPA were measured with a fiber-based 1550 nm time-resolved differential transmission (∆T) set-up. The InGaAs-based materials show a positive ∆T with sub-picosecond lifetime, whereas ErAs:GaAs shows a negative ∆T consistent with a two-photon absorption process.
2. FAQ for InP Epitaxial Growth
Q1: Have you done any optical measurements on those undoped wafers- such as infrared reflection and transmission? If yes, can you please send me that information?
A: Infrared reflection and transmission data is for transparent substrate detection, but for epi wafer, even if the substrate is double side polished, after epitaxy, the back will also be black, so that infrared reflection and transmission is not observed.
Q2: For InP-based growth, you don’t expect any problems with alloy ordering when using substrates without an off-cut?
A: It is ok, no ordering problem when using InP susbtrate without off-cut.
Source: PAM-XIAMEN, American Chemical Society
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