Comparative study of Cl₂, Cl₂/O₂, and Cl₂/N₂ inductively coupled plasma processes for etching of high-aspect-ratio photonic-crystal holes in InP

An extensive investigation has been performed on inductively coupled plasmaetching of InP. An important motivation for this work is the fabrication of high-aspect-ratio holes for photonic crystals. The essential chemistry is based on Cl₂ with the addition of N₂ or O₂ for sidewall passivation. The influence of different process parameters such as gas flows, temperature,pressure, ion energy, and inductively coupled plasma power on the hole geometry is presented. It is concluded that photonic crystals can be etched with Cl₂ only; however, temperature and pressure control is critical. Adding passivation gases largely broadens the window in the parameter space for hole etching. Most importantly, etching of narrow holes can be carried out at higher temperatures where the etching is mass limited and spontaneous etching of InP by Cl₂ occurs.Part of this research is supported by NanoNed, a technology program of the Dutch Ministry of Economic Affairs

Scanning Tunneling Microscope-Induced Luminescence Spectroscopy on Semiconductor Heterostructures

Scanning tunneling microscope (STM)-induced luminescence is explored as a technique for the characterization of semiconductor quantum wells and quantum wire heterostructures. By injecting minority carriers into the cleaved cross section of these structures, luminescence excitation on a nanometer scale is demonstrated. Using spectrally resolved STM-induced luminescence for the tip placed at various positions across the cleaved heterostructure, it is possible to obtain local spectroscopic information on closely spaced quantum structures

InP-based two-dimensional photonic crystals filled with polymers

Polymer filling of the air holes of Indium Phosphide based two-dimensional photonic crystals is reported. After infiltration of the holes with a liquid monomer and solidification of the infill in situ by thermal polymerization, complete filling is proven using scanning electron microscopy. Optical transmission measurements of a filled photonic crystal structure exhibit a redshift of the air band, confirming the complete filling.Comment: To be published in Appl. Phys. Let

Commodifying development experience: deconstructing development as gift in the development blockbuster

This paper discusses the recent rise of popular ‘blockbuster’ books written by international development industry insiders and produced by commercial publishers. The paper explores a set of common stylistic devices found within this emerging genre. Though each book is different, a key trope is the story of an author's earlier professional life—the hard lessons and gritty insights that have supposedly emerged from it—that normally underpins each narrative. By living the challenges involved in development work at first hand, and by making mistakes and experiencing epiphanies along the way, these author-professionals want readers to know that they have found out the hard way that long-cherished beliefs about development now need to be questioned. Readers are invited to relive these lessons and epiphanies, and to think and act differently about development by upholding a highly pragmatic form of development professionalism. Combining elements of research monograph, self-help book and personal memoir, these development blockbuster books can be understood not only as commodities, but also as part of the development gift. The authors promise a gift of experience but, in reality, these books are mundane commodities enmeshed in capitalist exchange relations