Pub Date : 2024-08-02DOI: 10.1109/JSTQE.2024.3437193
Maryam Sadat Amiri Naeini;Pierre Berini
Wafer-level testing is an important step for process and quality control of electronic chips in integrated circuit (IC) manufacturing which occurs before packaging. The process of wafer probing in its conventional contacting schemes, becomes more complicated as ICs move to smaller technology nodes and more compact designs, greatly increasing testing costs. Non-contact optical wafer probing can overcome physical probing complications, reducing costs, and increasing throughput and reliability. In this article, a CMOS compatible, broadband (22 GHz), small footprint (5 μm dia.) plasmonic electro-optic modulator of low insertion loss (4 dB) and wide optical working bandwidth (100 nm) is proposed and demonstrated as a potential solution for wafer-level optical testing. The device modulates in reflection an incident optical carrier emerging from an optical fiber in a non-contact arrangement, to work as a data output channel from the wafer. A modulation depth of over 2% is achieved which should be sufficient to meet the requirements of wafer-level testing. The device can be placed anywhere on wafer.
{"title":"High-Speed Electro-Optic Plasmonic Modulator for CMOS Non-Contact Wafer-Level Testing","authors":"Maryam Sadat Amiri Naeini;Pierre Berini","doi":"10.1109/JSTQE.2024.3437193","DOIUrl":"10.1109/JSTQE.2024.3437193","url":null,"abstract":"Wafer-level testing is an important step for process and quality control of electronic chips in integrated circuit (IC) manufacturing which occurs before packaging. The process of wafer probing in its conventional contacting schemes, becomes more complicated as ICs move to smaller technology nodes and more compact designs, greatly increasing testing costs. Non-contact optical wafer probing can overcome physical probing complications, reducing costs, and increasing throughput and reliability. In this article, a CMOS compatible, broadband (22 GHz), small footprint (5 μm dia.) plasmonic electro-optic modulator of low insertion loss (4 dB) and wide optical working bandwidth (100 nm) is proposed and demonstrated as a potential solution for wafer-level optical testing. The device modulates in reflection an incident optical carrier emerging from an optical fiber in a non-contact arrangement, to work as a data output channel from the wafer. A modulation depth of over 2% is achieved which should be sufficient to meet the requirements of wafer-level testing. The device can be placed anywhere on wafer.","PeriodicalId":13094,"journal":{"name":"IEEE Journal of Selected Topics in Quantum Electronics","volume":"30 4: Adv. Mod. and Int. beyond Si and InP-based Plt.","pages":"1-9"},"PeriodicalIF":4.3,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141883752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lithium Niobate is a ferroelectric material with interesting physical properties. In particular, Periodically Poled Lithium Niobate (PPLN) crystals have been used in diverse applications, such as non-linear optics or microlens array fabrication. In this work, we used a PPLN crystal having hexagonal reversed polarization domains, disposed on a square array of 200 µm period. We applied a temperature gradient to the PPLN and simultaneously observed it with a lensless incoherent holographic microscope. We observed that the phase of the inverse polarization domains varied depending on the temperature applied. Therefore, we induced a thermo-optical modulation of the PPLN crystal. We further analysed the behaviour of the PPLN, propagating the complex field beyond the crystal and plotting its intensity. We found that an elongated bright spot was formed at the centre of each hexagonal reversed polarization domain, due to diffraction. Given their shape and the nature of the phenomenon, these intensity spots are similar to Poisson spots. The intensity of the spots depended on the phase of the PPLN (hence, on the temperature applied). Therefore, we were able to generate a tunable Poisson spot array by controlling the temperature of the PPLN.
{"title":"Thermo-Optical Modulation of PPLN Crystal for Tunable Poisson Spot Array","authors":"Nicolo Incardona;Jaromir Behal;Veronica Vespini;Sara Coppola;Vittorio Bianco;Lisa Miccio;Simonetta Grilli;Manuel Martinez-Corral;Pietro Ferraro","doi":"10.1109/JSTQE.2024.3434659","DOIUrl":"10.1109/JSTQE.2024.3434659","url":null,"abstract":"Lithium Niobate is a ferroelectric material with interesting physical properties. In particular, Periodically Poled Lithium Niobate (PPLN) crystals have been used in diverse applications, such as non-linear optics or microlens array fabrication. In this work, we used a PPLN crystal having hexagonal reversed polarization domains, disposed on a square array of 200 µm period. We applied a temperature gradient to the PPLN and simultaneously observed it with a lensless incoherent holographic microscope. We observed that the phase of the inverse polarization domains varied depending on the temperature applied. Therefore, we induced a thermo-optical modulation of the PPLN crystal. We further analysed the behaviour of the PPLN, propagating the complex field beyond the crystal and plotting its intensity. We found that an elongated bright spot was formed at the centre of each hexagonal reversed polarization domain, due to diffraction. Given their shape and the nature of the phenomenon, these intensity spots are similar to Poisson spots. The intensity of the spots depended on the phase of the PPLN (hence, on the temperature applied). Therefore, we were able to generate a tunable Poisson spot array by controlling the temperature of the PPLN.","PeriodicalId":13094,"journal":{"name":"IEEE Journal of Selected Topics in Quantum Electronics","volume":"30 4: Adv. Mod. and Int. beyond Si and InP-based Plt.","pages":"1-8"},"PeriodicalIF":4.3,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10613376","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141864296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-29DOI: 10.1109/JSTQE.2024.3434581
Rutwik Joshi;Luke F. Lester;Mantu K. Hudait
In this work, we propose aninitial framework and present numerical estimates for designing a GeSn-based quantum well (QW) laser that can attain efficient lasing, while utilizing a monolithic lattice matched (LM) InGaAs/GeSn/InGaAs stack. GeSn QW emission characteristics depend significantly on the quantized energy level as the bulk bandgap reduces and approaches zero for high Sn. One factor that diminishes the quantum efficiency of light sources is the defects present within the active region, which result in non-radiative recombination. Furthermore, defects at the interface can hinder the band alignment causing loss of carrier confinement. InGaAs, InAlAs and a well-designed LGB can provide large band offsets with GeSn to form a type I separate confinement heterostructure (SCH) QW laser structure while enabling a virtually defect-free active region suitable for room temperature operation and scalable to an arbitrary number of QWs. When LM, the InAlAs and InGaAs layers provide a large total band offset of ∼1.1eV and ∼0.6eV, respectively. For a 10 nm GeSn QW SCH laser, a threshold current (J TH