LED Devices (Mini-, Micro- LED)  

 In the realm of LED production, factors such as cost efficiency and technical specifications like light output (LOP) and forward voltage (Vf) have traditionally held sway. However, with the advent of MicroLED technology, new challenges have taken center stage, particularly in this nascent phase: 

• The significantly thinner structures of MicroLEDs underscore the critical importance of achieving uniform thickness across wafers and ensuring repeatability from batch to batch. 
• These structures, often two orders of magnitude smaller, demand even tighter control over particles to meet the stringent device yield requirements. 

To meet the exacting standards of MicroLED fabrication, the adoption of automated load lock systems is imperative. These systems maintain process chambers under continuous vacuum, ensuring optimal process stability and minimizing particle contamination. Furthermore, eliminating manual handling at the front-end reduces errors and enables precise tracking of each wafer throughout production. 

Similar to traditional LED manufacturing, a holistic understanding of the entire LED process chain is paramount. Leveraging our extensive experience and close collaboration with clients, we recognize that optimal device performance and yield stem from fine-tuning individual processes as part of a comprehensive package. Here's a brief overview of the processes where we excel in adding value for our customers: 

In the early stages of MicroLED technology development, various manufacturing approaches, including "mass transfer" and "monolithic," are being explored. Evatec's expertise in TCOs (ITO, AZO), Mirrors (DBR, Ag), and Metals (Ni, Ti, Pt, Au, WTi) enables us to support both methods with the deposition of high-transmission films across the entire visible spectrum. 

You can read more about Evatec production platform and processes for Micro LED in LAYERS 8.

Laser Diodes (VCSEL, EEL)  

Laser diodes, encompassing Vertical-Cavity Surface-Emitting Lasers (VCSEL) and Edge-Emitting Lasers (EEL), play a pivotal role in advancing 3D sensing technology. While applications like face recognition in mobile phones have already embraced 3D sensing, emerging sectors such as Autonomous Driving necessitate tailored solutions based on time-of-flight (TOF) with Near-Infrared (NIR) VCSEL and EEL technologies. Additionally, shortwave VCSELs and blue VCSELs are garnering attention for their potential in diverse applications like data communications, 3D printing, chip-sized atomic clocks, and high-brightness light sources. 

Similar to our expertise in LED technology, Evatec boasts a wealth of knowledge across various processes in the manufacturing chain for VCSEL and EEL technologies. With over 15 years of experience in providing manufacturing solutions for Distributed Bragg Reflectors (DBRs), Transparent Conductive Oxides (TCOs), metals, and passivation layers in LED applications, we possess the expertise to tailor thin film processes for VCSEL and EEL in collaboration with our customers. 

Unlike LEDs, where photons typically undergo single reflection within the active region, VCSEL cavities facilitate multiple reflections. Therefore, achieving high reflectivities on both front and back sides of DBRs is crucial to mitigate light output losses. 

Sputtered DBR layers offer several performance advantages over traditional epitaxial layers, particularly in the blue domain, including: 

You can read more about Evatec production platforms and processes for VCSEL and EEL, including new processes for enhanced side wall coverage enabling a wafer level optics approach to EEL manufacturing, in the LAYERS articles below.