In-situ metrology system maker LayTec AG of Berlin, Germany says that, following the request of customers and utilizing the modular concept of its new Gen3 in-situ platform, it has customized and expanded the related in-situ metrology performance for vertical-cavity surface-emitting laser (VCSEL) epitaxy. VCSELs grown on gallium arsenide (GaAs) are currently emerging as a leading technology in rapidly expanding markets such as gesture recognition, 3D imaging, datacom and others. In May, one of LayTec's lead users in Europe placed the first order for such a system (the EpiTT/VCSEL), to be shipped by the beginning of 2017.
The EpiTT/VCSEL contains two fiber-optical heads: one for a standard EpiTT and one for spectral reflectance sensing (R-VCSEL). Both can also be mounted via an adapter flange on an EpiCurve head, making an EpiCurveTT/VCSEL system (as shown in Figure 1). This allows integration of full EpiCurveTT performance with the spectral monitoring of distributed Bragg reflector (DBR) stop-bands and cavity dip position. In Figure 1, this 4-in-1 metrology tool is mounted atop an Aixtron G3 Planetary metal-organic chemical vapor deposition (MOCVD) reactor.
Figure 1: EpiCurve TT/VCSEL – the four dimensions for VCSEL epi: measured feature #1 – wafer temperature (EpiTT head), #2 – growth rates (EpiTT head), #3 – wafer bow (EpiCurve head), #4 – spectral reflectance (R-VCSEL head) – all sensing through the purged view-port of an Aixtron G3 Planetary MOCVD reactor.
The EpiTT/VCSEL and EpiCurveTT/VCSEL are powered by new software modules that enable both single-pocket and multi-pocket operation.
