Fast and easy growth analysis on Patterned Sapphire Substrates (PSS)

In the next years, the use of PSS will further increase due to its high light extraction efficiency. Following this trend, LayTec‘s in-situ metrology software EpiNet 2 can be individually customized for various kinds of PSS. Our users can expand the substrate database by themselves. LayTec‘s Calibration Manual explains how to measure PSS reflectance in different pockets in one single calibration run. If required, LayTec also offers related customer trainings. Once the initial reflectance values of the PSS substrates are uploaded, the operator can choose the needed substrate in the RunType‘s Material Spec window (Fig. 1). As a result, all PSS wafers can be monitored with the same accuracy as standard sapphire substrates.


Fig. 1: Extract of a Run-Type’s Material Spec window of LayTec‘s EpiNet 2 software with a customized database extended by additional PSS types.

Fig. 2 shows a GaN growth on PSS. The initial 405 nm reflectance on the bare PSS substrate is „noisy“ because it senses the local non-uniformity of the PSS structure. As soon as GaN buffer is thick enough, this „noise“ reduces because the 405 nm light does not reach the PSS pattern anymore through the UV absorbing GaN. The increasing reflectance of all 3 wavelengths after ~4000 s shows the coalescence process of GaN. After ~8050 s, the 405 nm reflectance stays stable at 15.5%, which is an indication of the GaN surface quality improvement. However, the interference patterns of the 633/950 nm reflectance look „noisy“ during 2 D buffer growth. Obviously, the initial non-uniformity of the PSS structure causes a certain non-uniformity in the GaN thickness.


Fig. 2: GaN growth on PSS measured by EpiCurve®TT at FBH, Berlin, Germany: reflectance at 405 nm (blue), 633 nm (green), 950 nm (red); True Temperature (black).

Alongside with the customized database, EpiNet 2 also provides fitting of thin layers, wafer bow calculation and many further features indispensable for growth on PSS. Learn more in EpiNet 2 datasheet by contacting sales@laytec.de.

Disclaimers of Warranties
1. The website does not warrant the following:
1.1 The services from the website meets your requirement;
1.2 The accuracy, completeness, or timeliness of the service;
1.3 The accuracy, reliability of conclusions drawn from using the service;
1.4 The accuracy, completeness, or timeliness, or security of any information that you download from the website
2. The services provided by the website is intended for your reference only. The website shall be not be responsible for investment decisions, damages, or other losses resulting from use of the website or the information contained therein<
Proprietary Rights
You may not reproduce, modify, create derivative works from, display, perform, publish, distribute, disseminate, broadcast or circulate to any third party, any materials contained on the services without the express prior written consent of the website or its legal owner.

Today Philips Lumileds launches its proprietary CrispWhite Technology, yet another quality of light breakthrough in its portfolio, making whites appear vivid and bright while colors appear saturated. LUXEON CoB arrays with CrispWhite Technolog... READ MORE

For the first time there is a compact laser multi-chip package. Osram Opto Semiconductors can pack up to 20 blue laser chips in the new PLPM4 450 module. Instead of taking the laborious approach and constructing a light source from individual ... READ MORE