Impurity free vacancy diffusion induced quantum well intermixing based on hafnium dioxide films

Lin, Tao; Zhang, Haoqing; Sun, Hang; Yang, Chen; Lin, Nan

doi:10.1016/j.mssp.2014.01.032

Cited by 5 publications

(1 citation statement)

References 13 publications

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“…This might be due to complete inhabitation of intrinsic defects, possible oxygen vacancies, in the 100-nm thick HfO 2 film by Ga outdiffusion. 34 In addition, the alteration of strain at the HfO 2 ∕GaAs interface (possibly from thermal matching to tensile strained GaAs surface region) at elevated annealing temperatures could also play a role in suppressing the interdiffusion process. 27 15 Alternatively, SAQDs deposited with the SrTiO 3 film are found to be a highly effective cap for intermixing suppression, as depicted in Fig.…”

Section: Plasma-enhanced Chemical Vapor Depositionmentioning

confidence: 99%

InAs/GaAs quantum-dot intermixing: comparison of various dielectric encapsulants

et al. 2015

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Abstract. We report on the impurity-free vacancy-disordering effect in InAs/GaAs quantum-dot (QD) laser structure based on seven dielectric capping layers. Compared to the typical SiO 2 and Si 3 N 4 films, HfO 2 and SrTiO 3 dielectric layers showed superior enhancement and suppression of intermixing up to 725°C, respectively. A QD peak ground-state differential blue shift of >175 nm (>148 meV ) is obtained for HfO 2 capped sample. Likewise, investigation of TiO 2 , Al 2 O 3 , and ZnO capping films showed unusual characteristics, such as intermixing-control caps at low annealing temperature (650°C) and interdiffusion-promoting caps at high temperatures (≥675°C). We qualitatively compared the degree of intermixing induced by these films by extracting the rate of intermixing and the temperature for ground-state and excited-state convergences. Based on our systematic characterization, we established reference intermixing processes based on seven different dielectric encapsulation materials. The tailored wavelength emission of ∼1060─1200 nm at room temperature and improved optical quality exhibited from intermixed QDs would serve as key materials for eventual realization of low-cost, compact, and agile lasers. Applications include solid-state laser pumping, optical communications, gas sensing, biomedical imaging, green-yellow-orange coherent light generation, as well as addressing photonic integration via areaselective, and postgrowth bandgap engineering.

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Section: Plasma-enhanced Chemical Vapor Depositionmentioning

confidence: 99%