Formation of coupled-cavities in quantum cascade lasers using focused ion beam milling. Issue 9 (August 2015)

• Record Type: Journal Article
• Authors: Czerwinski, Andrzej; Pluska, Mariusz; Łaszcz, Adam; Ratajczak, Jacek; Pierściński, Kamil; Pierścińska, Dorota; Gutowski, Piotr; Karbownik, Piotr; Bugajski, Maciej
• Is Part Of: Microelectronics and reliability. Volume 55:Issue 9/10(2015)
• Page Start: 2142
• Page End: 2146
• Publication Date: 2015-08
• Subjects: Quantum cascade lasers -- QCL -- Coupled cavities -- CC-QCL -- Focused ion beam -- FIB; Electronic apparatus and appliances -- Reliability -- Periodicals; Miniature electronic equipment -- Periodicals; Appareils électroniques -- Fiabilité -- Périodiques; Équipement électronique miniaturisé -- Périodiques; Electronic apparatus and appliances -- Reliability; Miniature electronic equipment; Periodicals; 621.3815
• DOI: 10.1016/j.microrel.2015.06.111
• Languages: English
• ISSNs: 0026-2714

Abstract

Abstract: Focused ion beam (FIB) systems have become very useful tools used in the nanotechnology because they provide easy prototyping or post-processing customization of individual devices. A practical application of such post-processing is modification of monolithic quantum cascade laser (QCL) to obtain the structure with coupled cavities (CC-QCL), enabling its single mode performance, critical in many QCL applications. In-situ electrical measurements of the test structures showed that the main problem is avoiding a secondary deposition of the milled material. The redeposition can significantly reduce the performance and reliability of lasers. An avoidance of FIB imaging after final FIB cleaning of walls was revealed as an important factor leading to high quality of structures. The paper describes the solution by developing appropriate patterning procedure. This enabled the formation of exemplary single mode CC-QCLs with excellent performance at 9.45 μm wavelength with 30 dB side-mode suppression ratio, operating at room temperature. Performance of obtained single-mode coupled cavity quantum cascade lasers was stable, repeatable and no reliability problems were observed. Highlights: Coupled cavity QCLs were manufactured by FIB modification of monolithic QCLs. Single mode at wavelength of 9.45 μm was obtained at room temperature. 30 dB side-mode suppression ratio was achieved. Redeposition in FIB was minimized by developing appropriate patterning procedure. Performance was stable, repeatable and no reliability problems were observed.