High spatial resolution micro‐Raman temperature measurements of nitride devices (FETs and light emitters)

Abstract

Knowledge of the temperature in the active area of III‐nitride semiconductor devices such as AlGaN/GaN HFETs is essential for optimizing device design, performance and reliability, however, direct measurement of this temperature is not readily achieved. Infrared techniques often employed to measure the temperature of an active device are not well suited for AlGaN/GaN HFETs due to their limited spatial resolution when compared with the only micron‐size source‐drain device openings. The novel use of micro‐Raman spectroscopy for in‐situ measurements of device temperature, i.e., self‐heating effects, in single‐ and multi‐finger AlGaN/GaN HFETs with micrometer‐size resolution is discussed. Effects of device design on device temperature are illustrated. Variations in device temperature over a full wafer are studied considering that device reliability is strongly affected by device temperature. Applications of the technique to opto‐electronic devices in particular to InGaN/GaN laser diodes are also presented. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Efficient 3D-TLM Modeling and Simulation for the Thermal Management of Microwave AlGaN/GaN HEMT Used in High Power Amplifiers SSPA

“…This measurement technique uses a Renishaw micro-Raman system with 488 nm line of an Ar + ion laser as excitation source. More details about the use of micro-Raman Spectroscopy for active device temperature measurements can be found in References [18,22,23,41]. As part of the aim of measuring the profile temperature distribution by micro-Raman spectroscopy, a Radio Frequency amplifier for satellite applications, operating in S-band (2-4 GHz), was taken as described in Figure 3b.…”

“…Up to now, the temperature measurement of HEMTs could be made with infrared cameras [16], liquid crystal thermography [17], micro-Raman thermography [18], photoluminescence [19], transient thermo-reflectance [20], and pulsed current versus voltage measurements methods. These methods can be expensive and limited by the spatial resolution that may cause problems in measurement precision of the hotspot temperature.…”

“…We focused in this analysis on a 3-D distribution of the temperature, thermal behavior, self-heating and channel temperature. Furthermore, Micro-Raman Spectroscopy experience method performed by Kuball et al [18,22] was used to compare the detailed temperature distribution of the device, and the measurements are carried out for the verification of the 3D TLM model. We selected Micro-Raman spectroscopy as the Infrared image technique because of the spatial resolution on the order of 1 µm, which is required to accurately measure and explore the peak temperature of AlGaN/GaN HEMT with their narrow source-drain opening.…”

Assembly of CdSe/ZnS nanocrystals on microwires and nanowires for temperature sensing

“…Instead, other methods have been developed, e.g. Raman spectroscopy [5] and Scanning Thermal Microscopy [6]. These methods, on the other hand, typically show low performance in terms of temporal resolution and are rather expensive.…”

Diode junction temperature in ultraviolet AlGaN quantum-disks-in-nanowires

“…9 Specifically, prolonged current injection leads to higher T j which drastically degrades the LED performance, thereby causing catastrophic device failure. Various methods have been employed for measuring the junction temperature such as Raman spectroscopy, 10 thermal resistance, 11 photoluminescence, 12 nematic liquid crystals, 13 electroluminescence (EL) (band peak shift and high-energy slope of the spectrum), 14 and diode forward voltage. 15 Among these, the forward voltage method is considered the most accurate, though a precise calibration is needed for each device under test.…”