Loading...
News Article

US team optimises QCL laser epitaxy with EpiCurve TT

To improve performance, interface grading effects must be included in calculations

Fig. 1: In-situ measurements of AlInAs/GaInAs MQWs: reflectance at 450nm (blue) and wafer curvature (black): (a) Varying GaInAs well layer thickness dw with constant 10nm AlInAs barrier layer thickness dB (b) Varying AlInAs barrier layer thickness dB with constant GaInAs 10nm well layer thickness dw

Using Laytec's EpiTT in-situ system metrology tool,  Christine Wang and colleagues at the MIT Lincoln Laboratory (USA) have published two major findings on improving the MOCVD growth of InP-based QCLs in a Veeco D-125 multiwafer (3x2 inch) reactor.

First, that the growth of high-performance QCL structures requires the deposition of a complex sequence of coupled quantum wells (AlInAs, GaInAs). During this process, the cumulative Indium surface segregation has to be carefully compensated in the growth recipe to keep the targeted lattice matched throughout the full QCL structure.

Second, that even under optimised growth conditions, a certain interface- grading is unavoidable, especially at the GaInAs-to- AlInAs interfaces. However, optimum QCL performance can be achieved by taking into account these interface grading effects in the calculations of the QCL target structure.

EpiCurve TT was the key to these findings, which were published last year in the Journal of Crystal Growth.

Fig. 1 a (top) shows in-situ reflectance at 450 nm and curvature of the two decisive MQW runs. Reflectance oscillations correspond to each barrier and well layer and each layer is easily resolved. In Fig. 1b (below), the high-resolution wafer bow sensing verified the compressive strain accumulation at the AlInAs-to- GaInAs interface. 

After recipe optimisation, the 450 nm reflectance could be used as a characteristic finger-print of the formation of every single graded interface among the hundreds constituting a single QCL layers.

Say hello to the heterogeneous revolution
Double heterostructure HEMTs for handsets
AlixLabs to collaborate with Linköping University
SiC MOSFETs: Understanding the benefits of plasma nitridation
Wolfspeed reports Q2 results
VueReal secures $40.5m to scale MicroSolid printing
Mitsubishi joins Horizon Europe's FLAGCHIP project
Vishay launches new high voltage SiC diodes
UK team leads diamond-FET breakthrough
GaN adoption at tipping point, says Infineon
BluGlass files tuneable GaN laser patents
QD company Quantum Science expands into new facility
Innoscience files lawsuit against Infineon
Riber revenues up 5% to €41.2m
Forvia Hella to use CoolSiC for next generation charging
Photon Design to exhibit QD simulation tool
Ortel transfers CW laser fabrication to Canada
Luminus adds red and blue multi-mode Lasers
PseudolithIC raises $6M for heterogeneous chiplet tech
Mesa sidewall design improves HV DUV LEDs
IQE revenue to exceed expectations
'Game-changing' VCSEL system targets clinical imaging
German start-up secures finance for SiC processing tech
Macom signs preliminaries for CHIPS Act funding
IQE and Quintessent partner on QD lasers for AI
EU funds perovskite tandems for fuel-free space propulsion
EU to invest €3m in GeSi quantum project
Transforming the current density of AlN Schottky barrier diodes
Turbocharging the GaN MOSFET with a HfO₂ gate
Wolfspeed launches Gen 4 SiC MOSFET technology
Report predicts high growth for UK's North East
Element Six unveils Cu-diamond composite
×
Search the news archive

To close this popup you can press escape or click the close icon.
Logo
x
Logo
×
Register - Step 1

You may choose to subscribe to the Compound Semiconductor Magazine, the Compound Semiconductor Newsletter, or both. You may also request additional information if required, before submitting your application.


Please subscribe me to:

 

You chose the industry type of "Other"

Please enter the industry that you work in:
Please enter the industry that you work in: