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Photoconductivity measurements and trap analysis of wide bandgap nitride semiconductors Equipped with a 355 nm laser (μ-PCD) or a 375 nm laser diode (MDP), the MDPmap as well as the MDpicts from Freiberg Instruments are suitable for photoconductivity measurements and trap analysis on wide-bandgap nitride semiconductors. The homogeneity of n-type doping can be analyzed by means of the photoconductivity (signal height). It is strongly dependent on the resistivity and the carrier lifetime. The usually long apparent lifetimes are caused by trapping centers in the samples. Deep traps in wide-bandgap semiconductors can be investigated by MDpicts in the temperature range from 30 K up to 800 K. Compared to related methods (e.g. DLTS), MDpicts is a contactless and nondestructive method which also allows the investigation of highly n-doped semiconductors. The trap activation energy can be determined from the slope of the Arrhenius plot or estimated by directly fitting the lifetime reduction as a function of temperature by τ(T)= τ 0 /((1+aexp-E A /kT)). From the value of E A ~ 1.0 eV the main defect in the unintentionally doped GaN sample (see Figure 2 left) can be assumed to be C N . Figure 1: Photoconductivity maps measured by MDP of four different Si doping concentrations in GaN layers. Figure 2: Examples of the MDpicts time constants as a function of inverse temperature for left an unintentionally doped GaN sample and right a Si-doped GaN sample. Related Solutions and Industries: Epitaxial Layers & Thin Films Matching Products MDP series MDpicts Temperature-Dependent Lifetime Measurement System for Advanced Material Analysis Learn more MDP series MDPmap Precision Lifetime Charachterization with Exceptional Sensitivity Learn more Get in touch Do not hesitate to contact us – we are available to assist you with any inquiries or requests. Use our inquiry tool or reach out via email: sales @ freiberginstruments.com

Software - SPS Studio Get in touch Do not hesitate to contact us – we are available to assist you with any inquiries or requests. Use our inquiry tool or reach out via email: sales @ freiberginstruments.com

Burkhard Winkler Idea generator and Senior Sales Engineer for semiconductors and automation I came up with the idea for Ingot XRD Wire Saw, which immediately convinced our customers. Burkhard Winkler Senior Sales Engineer – SEMI / Automation Burkhard has been developing concepts for new machines and systems at Freiberg Instruments for 5 years, based on customer problems. This also includes costing and preparing quotations. He is responsible for the technical support of major projects, customer communication, and creates product specifications and catalogs. If necessary, he also takes on service activities and quality control. Burkhard is versatile and we are happy to have him in #TeamFI. Burkhard, tell us about your first touchpoint with FI. I was a supplier to Freiberg Instruments for mechanics, design and components. I quickly realized that FI was the perfect place for me to drive challenging projects forward and work with international customers on an equal footing. What skills should a new colleague in your department have? Clearly: good customer communication, openness and curiosity for innovation are essential. You shouldn't ignore problems, but actively tackle them. In addition, specialist training or experience in this area is of course helpful. What do you associate with our guiding principle, “Driven by Innovation”? Innovation is at the heart of our work. I love developing creative solutions and breaking new ground to meet our customers' needs. What else do you want to achieve with FI in the future? From a customer perspective, reliability is crucial. I want to improve our high standards even further, take on even more responsibility and never shy away from a challenge. What are you particularly proud of? I came up with the idea for the Ingot XRD Wire Saw, which immediately convinced our customers. This machine takes the accuracy of wafer sawing to a new level that is unique in the world and is now being produced in small series. It is already being used in production at a leading silicon manufacturer - a special moment in my career. How do you balance your job? I make music, love nature, water and winter sports. I also enjoy spending time with my family. Burkhard is Driven by Innovation Let's drive innovation together Current job openings Get to know the team Dr. Viktoriia Nikonova Productmanager Surface Photovoltage Spectroscopy Learn more Dr. Christian Hagendorf Projekt- & Key Account Manager XRD Series Learn more Martin Ferkinghoff Head of Service Learn more Marcus Richter Application & Service Engineer XRD Learn more Diana Trinks Assistant to the management Learn more Marcus Göhler Head of Electronics Development Learn more Thanga Kumar Global Sales Director Learn more Dr. Nadine Schüler Head of Research and Development Learn more

Marcus Richter Application & Service Engineer in the XRD area We solve measurement problems that others struggle with. Marcus Richter Application & Service Engineer Marcus has been supporting the #application of our various product lines for over 1.5 years. He is responsible for the installation and maintenance of our measuring devices worldwide. In the XRD area, he is responsible for commissioning and calibrating the X-ray measuring devices. Marcus, what was your first point of contact with FI? I became aware of Freiberg Instruments through my former employer, one of the world's leading manufacturers of silicon wafers. By chance, there was an interesting and suitable position for me at the time. Then everything happened very quickly and a short time later I was already part of #TeamFI. Why did you choose FI? It was the positive vibe of the team and the impressive expertise in highly complex processes - I wanted to be a part of that. Part of a team that makes a difference. What are you particularly proud of? In one of my first projects at FI, we supported the construction of a new production line for a big player in the silicon wafer industry. Our measuring tools are used to determine the geometry of the silicon ingot using X-ray diffraction and precisely align the position of the rod piece with the adhesive module. This complex process prepares the sawing process in which the ingot is cut into wafers. When the production line went into operation in Asia, we received a standing ovation from our customers. A great feeling and great recognition for our work. The biggest challenge in your job? With so many projects and tasks, it is sometimes not so easy to keep an eye on the essentials and maneuver through the challenges with a clear head. What makes Freiberg Instruments special for you? We solve problems that others struggle with. Together we are shaping the future of measurement technology. At Freiberg Instruments I can develop myself further, absorb knowledge and apply it worldwide. What is your balance to your job? I am a passionate guitarist and singer and spend a lot of time with my stoner rock band. We are currently recording our second album and hope to be back on the road in many small clubs soon. However, traveling and spending time with my family in our old VW Syncro bus all over the world is my biggest and best balance. Marcus is Driven by Innovation Let's drive innovation together Current job openings Get to know the team Dr. Viktoriia Nikonova Productmanager Surface Photovoltage Spectroscopy Learn more Dr. Christian Hagendorf Projekt- & Key Account Manager XRD Series Learn more Martin Ferkinghoff Head of Service Learn more Burkhard Winkler Senior Sales Engineer for semiconductors and automation Learn more Diana Trinks Assistant to the management Learn more Marcus Göhler Head of Electronics Development Learn more Thanga Kumar Global Sales Director Learn more Dr. Nadine Schüler Head of Research and Development Learn more

Dr. Nadine Schüler Communicator and mastermind We always try to keep our finger on the pulse. It motivates me immensely to be part of a company that makes a significant contribution to overcoming challenging measurement problems. Dr. Nadine Schüler Head of Research & Development As part of the company's rapid growth from the very beginning, Nadine made a decisive contribution to the development of devices that are now used as standard by numerous companies for material characterization. She currently leads research and development in #TeamFI, focusing on research projects with external partners such as universities and research institutes. Nadine, what was your first point of contact with Freiberg Instruments? I was already working with Dr. Kay Dornich and Prof. Jürgen Niklas, the founders of the company, at the TU Bergakademie Freiberg and they asked me if I would like to be part of something with great potential. Why did you choose Freiberg Instruments? I had the chance to be there from the very beginning and to learn a lot in very different areas. I liked that and the diverse development topics. I also had the support to complete my doctorate in physics. What skills are crucial for your field? At Freiberg Instruments, we solve complex problems. You need to enjoy the challenge, motivate yourself and actively look for solutions - while constantly tackling new issues in a wide range of specialist areas. How is your professional development supported? Many management tasks are now part of my area of responsibility. FI offers me guidance, support and training to help me develop further. What drives you? We always try to be at the cutting edge. It motivates me immensely to be part of a company that makes a significant contribution to overcoming demanding measurement problems and can therefore help solve the important challenges of our time. That's what drives me. Your best FI moment? Difficult question, simple answer: I am delighted every time a customer says that our device and service is better than the competition and that they have been able to solve problems that previously seemed unsolvable. Nadine is Driven by Innovation Let's drive innovation together Current job openings Get to know the team Dr. Viktoriia Nikonova Productmanager Surface Photovoltage Spectroscopy Learn more Dr. Christian Hagendorf Projekt- & Key Account Manager XRD Series Learn more Martin Ferkinghoff Head of Service Learn more Marcus Richter Application & Service Engineer XRD Learn more Burkhard Winkler Senior Sales Engineer for semiconductors and automation Learn more Diana Trinks Assistant to the management Learn more Marcus Göhler Head of Electronics Development Learn more Thanga Kumar Global Sales Director Learn more

Diana Trinks Organizer, decision-maker and fire extinguisher Always striving forward, rethinking and developing something new from what we have learned. Diana Trinks Executive Assistant Diana has been an important pillar at Freiberg Instruments for over 13 years. As assistant to the management, she acts as a sparring partner and keeps the business running in the background with quick decisions. She previously worked in purchasing and warehousing. Diana, tell us about your first contact with FI. When I was looking for a new job, I spoke to my dancing girls from the carnival club. Mrs. Dornich, Kay's wife (founder and CEO), was one of them at the time. FI was looking for someone for the warehouse and purchasing - the challenge sounded exciting to me. I really enjoyed the trial working day. It was a new field for me, but it was exciting and a perfect interpersonal match. What do you associate with our guiding principle “Driven by Innovation”? Always striving forward, rethinking and developing new things from what we have learned. The guiding principle motivates us to keep inventing new, good and important things. What drives you? Whether it's visiting trade fairs, daily business or preparing evaluations - every day is different and presents new challenges. That's what motivates and drives me. What skills should a new colleague bring to your department? In a nutshell: A healthy dose of pragmatism is a great advantage. What are you particularly proud of? I didn't stop at my initial tasks. I have continued to develop and can therefore provide support in many areas wherever I am needed. How does FI support your professional development? I can concentrate on what I'm good at. I also receive various training courses that help me to become even better and sharpen my focus. What do you do to balance your job? I dance, enjoy spending time with my children and like to help out in my learned profession of gastronomy. Diana is Driven by Innovation Let's drive innovation together Current job openings Get to know the team Dr. Viktoriia Nikonova Productmanager Surface Photovoltage Spectroscopy Learn more Dr. Christian Hagendorf Projekt- & Key Account Manager XRD Series Learn more Martin Ferkinghoff Head of Service Learn more Marcus Richter Application & Service Engineer XRD Learn more Burkhard Winkler Senior Sales Engineer for semiconductors and automation Learn more Marcus Göhler Head of Electronics Development Learn more Thanga Kumar Global Sales Director Learn more Dr. Nadine Schüler Head of Research and Development Learn more

Marcus Göhler Head of Electronics Development I want to translate the innovative strength of Freiberg Instruments into smart products. Dipl. Ing. Marcus Göhler Head of Electronics Development He has been a source of ideas, problem solver and critic for over 12 years. Enthusiastic about innovative technology and a wide range of design options, he is a graduate engineer who develops measurement and control electronics. By returning to his home country, Marcus is building on the values of the company - reliability, initiative and appreciation. Marcus, what do you associate with our guiding principle “Driven by Innovation”? We are always looking for new approaches to solving problems. In doing so, we use the latest technical possibilities and have already given many a competitor restless nights. What expectations did you have when you started at FI? After developing microchips and power plant control software, I wanted to familiarize myself with measurement technology, which was a new career field for me at the time. The interdisciplinary design possibilities were very appealing to me. What is your motivation? The idea that our ideas and the resulting new measurement techniques would make it possible to improve materials. Materials that are the basis for the major issues of our time, such as the energy transition. What are you particularly proud of? I am proud of the development of several universal electronic platforms that are used in many of our devices. We have also developed a completely new measurement technology that, for the first time, makes it possible to determine the electrical properties of raw materials for the latest power semiconductors during production. It's also really cool that we were able to give one of the major semiconductor manufacturers a significant market advantage with our X-ray measurement technology. What does someone working in your field need? A sound knowledge of electrical engineering is crucial, as is of course an openness to new technologies. But above all, you should enjoy solving problems. You should be #DrivenByInnovation. Marcus is Driven by Innovation Let's drive innovation together Current job openings Get to know the team Dr. Viktoriia Nikonova Productmanager Surface Photovoltage Spectroscopy Learn more Dr. Christian Hagendorf Projekt- & Key Account Manager XRD Series Learn more Martin Ferkinghoff Head of Service Learn more Marcus Richter Application & Service Engineer XRD Learn more Burkhard Winkler Senior Sales Engineer for semiconductors and automation Learn more Diana Trinks Assistant to the management Learn more Thanga Kumar Global Sales Director Learn more Dr. Nadine Schüler Head of Research and Development Learn more

Thanga Kumar Sales Director I like the spirit of Freiberg Instruments: innovative, team-oriented, dynamic. Thanga Kumar Sales Director He develops and implements sales strategies, maintains customer relationships and has been driving the business development of Freiberg Instruments for over 10 years. He wants to further drive the growth of #TeamFI and strengthen its position as a leading provider of measurement technology solutions. Thanga, why do you work at Freiberg Instruments? Freiberg Instruments is an extremely exciting company that has grown massively in recent years. Here I can constantly develop my skills and realize my full potential. I like the spirit of Freiberg Instruments: innovative, team-oriented, dynamic. What skills are crucial for your specialist area? Communication is the be-all and end-all. A technical understanding in the field of measurement technology helps to better understand our products. Sales experience is also important. Through continuous training, the promotion of further training opportunities and the chance to take on responsibility in various projects, I can constantly develop my skills at Freiberg Instruments. The biggest challenge in your job? We are in a dynamic, constantly changing market environment. Keeping pace with customer requirements and achieving our sales targets at the same time is a tough but also motivating challenge. Together, we can create real added value for our customers and drive the development of companies. Your best FI moment? In 2017, we received the Oskar Patzelt Foundation's Grand Prize for Small and Medium-Sized Enterprises for our innovative product development. A great moment for our entire team and incredibly nice recognition. How do you balance your job? Definitely traveling and getting to know new cultures. I currently have just over 60 country points, spread over 6 continents. My next destination: Peru and Bolivia. Thanga is Driven by Innovation Let's drive innovation together Current job openings Get to know the team Dr. Viktoriia Nikonova Productmanager Surface Photovoltage Spectroscopy Learn more Dr. Christian Hagendorf Projekt- & Key Account Manager XRD Series Learn more Martin Ferkinghoff Head of Service Learn more Marcus Richter Application & Service Engineer XRD Learn more Burkhard Winkler Senior Sales Engineer for semiconductors and automation Learn more Diana Trinks Assistant to the management Learn more Marcus Göhler Head of Electronics Development Learn more Dr. Nadine Schüler Head of Research and Development Learn more

Dr. Viktoriia Nikonova Product Manager - Surface Photovoltage Spectroscopy My role at Freiberg Instruments: Improve, refine, optimize. Dr. Viktoriia Nikonova Product Manager SPV/SPS Viktoriia has been contributing her expertise in surfaces for over a year. She researches and works on innovative methods to precisely analyze the surfaces of materials in order to make defects and qualities visible. Viktoriia, what was your first point of contact with Freiberg Instruments? I came across a job advertisement online and was invited to an interview after a short call. I was immediately impressed by the atmosphere, even though it was rather quiet on the day. I also had the opportunity to see Freiberg beforehand - the historic city center immediately captivated me with its charm. Why did you choose Freiberg Instruments? It was the first time that a job really matched my training. I immediately had the feeling that I could actively contribute my experience here. The team has broad expertise in the product development of measuring instruments - from hardware to software. So you can really make a difference. What are you working on at Freiberg Instruments? I am working on the Surface Photovoltage (SPV) method for our measuring instruments. This technique is one of the most advanced methods for analyzing semiconductors and other photoactive materials. It allows us to quickly and efficiently check surface qualities and defects in various materials - including highly doped materials and epi-layers. Your role at Freiberg Instruments in three words? Improve, refine, optimize. Your best moment at Freiberg Instruments? Definitely when I was on site with a customer to install our system. The support from the whole team was great and it felt really good. How does Freiberg Instruments support your professional development? FI gives me the opportunity to combine my scientific work with tasks that are important for the industry - that means a lot to me and helps me move forward. Viktoriia is Driven by Innovation Let's drive innovation together Current job openings Get to know the team Dr. Christian Hagendorf Projekt- & Key Account Manager XRD Series Learn more Martin Ferkinghoff Head of Service Learn more Marcus Richter Application & Service Engineer XRD Learn more Burkhard Winkler Senior Sales Engineer for semiconductors and automation Learn more Diana Trinks Assistant to the management Learn more Marcus Göhler Head of Electronics Development Learn more Thanga Kumar Global Sales Director Learn more Dr. Nadine Schüler Head of Research and Development Learn more

Contactless characterization of SiC, GaN and AlGaN Aim SiC, GaN and AlGaN belong to the class of wide band gap semiconductors and are applied especially in power electronics, optoelectronic devices and transistors such as HEMTs (high electron mobility transistor. The contactless optoelectronic characterization of wide band gap semiconductors and heterostructures under production conditions and in fields of R&D is often challenging. Solution SPV spectroscopy in the dc (Kelvin probe, measurement of the contact potential difference, DCPD) and ac (modulated) modes provides information about preferential directed charge separation in relation to electronic transitions and carrier dynamics [1]. The application of charge amplifiers allows for SPV measurements in dc and ac modes with the same electrode. Application example Figure 1 shows DCPD spectra of GaN, Al 0.25 Ga 0.75 N/GaN and 4h-SiC/GaN deposited onto sapphire wafers. Aside directions of charge separation and transition energies at band gaps, defect transitions can be distinguished. Signatures of slow processes can be discriminated in modulated SPV measurements (figure 2). References [1] Th. Dittrich, S. Fengler, “Surface photovoltage analysis of photoactive materials”, World Scientific, 2020. [2] Th. Dittrich, S. Fengler, N. Nickel, “Surface photovoltage spectroscopy over wide time domains for semiconductors with ultrawide bandgap: example of gallium oxide”, Phys. Stat. Sol. A 11 (2021) 2100176. Fig. 1: DCPD spectra of GaN (blue), Al0.26Ga0.74N / GaN (green) and 4h-SiC / GaN (red) epitaxial layers deposited on sapphire. Fig. 2: Modulated in-phase and phase-shifted by 90° SPV spectra of GaN (a), 4h-SiC / GaN (b) and Al0.26Ga0.74N / GaN (c). Related Solutions and Industries: Epitaxial Layers & Thin Films Matching Products SPS/SPV series HR-SPSmap with fixed energy excitation sources High-Resolution and Sensitive Surface Photovoltage Measurement Solutions Learn more SPS/SPV series HR-SPSmap with variable energy excitation source with a variable energy excitation source Learn more Get in touch Do not hesitate to contact us – we are available to assist you with any inquiries or requests. Use our inquiry tool or reach out via email: sales @ freiberginstruments.com