Advanced R&D (Research & Development)

LayTec’s metrology tools are of critical importance in the R&D labs of research organizations where new thin-film materials, processes and device structures are developed. Our strength lies in  understanding the demands of our customers and modifying and combining existing products into new systems that can be applied to an extremely wide range of R&D applications.

LayTec metrology speeds up process development on 100 mm (11-22) GaN / r-PSS

Dr. Frank Brunner of FBH Berlin, Germany  presented his latest results on growth of (11-22) GaN / r-PSS in an AIX 2600G3-HT reactor (8x4” config¬uration) at last week’s OMVPE Workshop in BigSky (Montana). Please find more details about "Large area heteroepitaxial (11-22) - GaN growth" in the following presentation.

EpiTT: speeding-up the R&D for GaN-epi on (WS₂, MoS₂) 2D substrates

Dr. Arnab Bhattacharya  of Tata Institute in Mumbai, India, reported on latest in-situ results for a completely new type of growth process: MOCVD of GaN on transition-metal dichalcogenides (WS₂, MoS₂).

Please find more details about "In-situ reflectometry of MOVPE-grown epilayers" in the following presentation.

In-situ photoluminescence of growing III-Nitride LED structures

In a collaboration between LayTec and Prof. Dirk Rueter´s group at University of Applied Sciences Ruhr West a break-through has been achieved regarding the real-time monitoring of InGaN/GaN quantum well emission wavelength during MOCVD growth. It is well known that room temperature wafer based photoluminescence (PL) measurements provide an excellent forecast of the emission wavelength and emission intensity of the later LED devices. This prototype in-situ PL system in [1] team workes at growth temperatures with LayTec Pyro 400 in a commercial multi-wafer MOCVD reactor. The related paper [1] was rocketed immediately to the status of  “most downloaded Journal of Crystal Growth articles”  from Science Direct. This  work is supported under grant KF3242801NT3 by BMWi (German Federal Government).

[1] C. Prall et al. in Journal of Crystal Growth 415 (2015), 1–6.

Fig.1: In-situ spectra of growing InGaN MQW structure (solid lines) at wafer temperature of 690 °C. The InGaN PL peak wavelength was extracted from Gaussian fits (dashed lines) to eliminate the FPOs.

In-situ metrology for graphene growth

For several years, graphene has been the subject of intense research activity aimed at exploiting its unique properties. Unbreakable and foldable touch screens for mobile phones, faster computer chips, batteries of higher capacity – these are just a few of graphene’s applications. Although the growth of graphene is a very new and complex process, we have developed a solution for in-situ reflectance analysis of the surface changes during the growth.

The first tests have been conducted during graphene growth on copper/silicon (Cu/Si) in a commercial CVD reactor. Our in-situ reflectometer has clearly demonstrated its sensitivity to surface processes like de-oxidation and roughening during graphene CVD on Cu. Furthermore, we could see that in case of growth on Cu/Si, the combination of temperature, low pressure and CH₄ supply does change the surface properties of the copper substrate and causes copper removal from the surface. Therefore, a sensor able to monitor in-situ both surface temperature and reflectance, like LayTec’s EpiTT, can deliver valuable information to understand and optimize the deposition process.

Further systematic in-situ studies by our academic customers will give new insights into the physics and chemistry of such processes, and complement the results of other, more complicated techniques as spectroscopic ellipsometry. For future large-scale production reactors, where ellipsometry ports usually cannot be easily integrated, either normal incidence 3-wavelength reflectance (EpiTT) or even UV/visible spectroscopic reflectance (EpiR DA TT) could serve as efficient in-situ metrology tools both for R&D and future process control.

For details of the study and the first tentative results please ask info@laytec.de for our Graphene Application Note.