Sacrificial structures for deep reactive ion etching of high-aspect ratio kinoform silicon x-ray lenses

Research output: Contribution to journalJournal articleResearchpeer-review

683 Downloads (Pure)

Abstract

This article describes the realization of complex high-aspect ratio silicon structures with feature dimensions from 100 lm to 100nm by deep reactive ion etching using the Bosch process. As the exact shape of the sidewall profiles can be crucial for the proper functioning of a device, the authors investigated how sacrificial structures in the form of guarding walls and pillars may be utilized to facilitate accurate control of the etch profile. Unlike other sacrificial structuring approaches, no silicon-on-insulator substrates or multiple lithography steps are required. In addition, the safe removal of the sacrificial structures was accomplished by thermal oxidation and subsequent selective wet etching. The effects of the dimensions and relative placement of sacrificial walls and pillars on the etching result were determined through systematic experiments. The authors applied this process for exact sidewall control in the manufacture of x-ray lenses that are very sensitive to sidewall shape nonuniformities. Compound kinoform lenses for focusing hard x-rays with structure heights of 200 lm were manufactured, and the lenses were tested in terms of their focusing ability and refracting qualities using synchrotron radiation at a photon energy of 17 keV. A 180 lm long line focus with a waist of 430 nm at a focal length of 215mm was obtained.
Original languageEnglish
Article number062001
JournalJournal of Vacuum Science and Technology. Part B. Microelectronics and Nanometer Structures
Volume33
Issue number6
Number of pages10
ISSN1071-1023
DOIs
Publication statusPublished - 2015

Bibliographical note

© 2015 American Vacuum Society

Cite this

@article{ecaa5591f16844848059dcbf6ab73006,
title = "Sacrificial structures for deep reactive ion etching of high-aspect ratio kinoform silicon x-ray lenses",
abstract = "This article describes the realization of complex high-aspect ratio silicon structures with feature dimensions from 100 lm to 100nm by deep reactive ion etching using the Bosch process. As the exact shape of the sidewall profiles can be crucial for the proper functioning of a device, the authors investigated how sacrificial structures in the form of guarding walls and pillars may be utilized to facilitate accurate control of the etch profile. Unlike other sacrificial structuring approaches, no silicon-on-insulator substrates or multiple lithography steps are required. In addition, the safe removal of the sacrificial structures was accomplished by thermal oxidation and subsequent selective wet etching. The effects of the dimensions and relative placement of sacrificial walls and pillars on the etching result were determined through systematic experiments. The authors applied this process for exact sidewall control in the manufacture of x-ray lenses that are very sensitive to sidewall shape nonuniformities. Compound kinoform lenses for focusing hard x-rays with structure heights of 200 lm were manufactured, and the lenses were tested in terms of their focusing ability and refracting qualities using synchrotron radiation at a photon energy of 17 keV. A 180 lm long line focus with a waist of 430 nm at a focal length of 215mm was obtained.",
author = "Frederik St{\"o}hr and Jonas Michael-Lindhard and J{\"o}rg H{\"u}bner and Flemming Jensen and Hugh Simons and Jakobsen, {Anders Clemen} and Poulsen, {Henning Friis} and Ole Hansen",
note = "{\circledC} 2015 American Vacuum Society",
year = "2015",
doi = "10.1116/1.4931622",
language = "English",
volume = "33",
journal = "Journal of Vacuum Science and Technology. Part B. Microelectronics and Nanometer Structures",
issn = "1071-1023",
publisher = "American Institute of Physics",
number = "6",

}

TY - JOUR

T1 - Sacrificial structures for deep reactive ion etching of high-aspect ratio kinoform silicon x-ray lenses

AU - Stöhr, Frederik

AU - Michael-Lindhard, Jonas

AU - Hübner, Jörg

AU - Jensen, Flemming

AU - Simons, Hugh

AU - Jakobsen, Anders Clemen

AU - Poulsen, Henning Friis

AU - Hansen, Ole

N1 - © 2015 American Vacuum Society

PY - 2015

Y1 - 2015

N2 - This article describes the realization of complex high-aspect ratio silicon structures with feature dimensions from 100 lm to 100nm by deep reactive ion etching using the Bosch process. As the exact shape of the sidewall profiles can be crucial for the proper functioning of a device, the authors investigated how sacrificial structures in the form of guarding walls and pillars may be utilized to facilitate accurate control of the etch profile. Unlike other sacrificial structuring approaches, no silicon-on-insulator substrates or multiple lithography steps are required. In addition, the safe removal of the sacrificial structures was accomplished by thermal oxidation and subsequent selective wet etching. The effects of the dimensions and relative placement of sacrificial walls and pillars on the etching result were determined through systematic experiments. The authors applied this process for exact sidewall control in the manufacture of x-ray lenses that are very sensitive to sidewall shape nonuniformities. Compound kinoform lenses for focusing hard x-rays with structure heights of 200 lm were manufactured, and the lenses were tested in terms of their focusing ability and refracting qualities using synchrotron radiation at a photon energy of 17 keV. A 180 lm long line focus with a waist of 430 nm at a focal length of 215mm was obtained.

AB - This article describes the realization of complex high-aspect ratio silicon structures with feature dimensions from 100 lm to 100nm by deep reactive ion etching using the Bosch process. As the exact shape of the sidewall profiles can be crucial for the proper functioning of a device, the authors investigated how sacrificial structures in the form of guarding walls and pillars may be utilized to facilitate accurate control of the etch profile. Unlike other sacrificial structuring approaches, no silicon-on-insulator substrates or multiple lithography steps are required. In addition, the safe removal of the sacrificial structures was accomplished by thermal oxidation and subsequent selective wet etching. The effects of the dimensions and relative placement of sacrificial walls and pillars on the etching result were determined through systematic experiments. The authors applied this process for exact sidewall control in the manufacture of x-ray lenses that are very sensitive to sidewall shape nonuniformities. Compound kinoform lenses for focusing hard x-rays with structure heights of 200 lm were manufactured, and the lenses were tested in terms of their focusing ability and refracting qualities using synchrotron radiation at a photon energy of 17 keV. A 180 lm long line focus with a waist of 430 nm at a focal length of 215mm was obtained.

U2 - 10.1116/1.4931622

DO - 10.1116/1.4931622

M3 - Journal article

VL - 33

JO - Journal of Vacuum Science and Technology. Part B. Microelectronics and Nanometer Structures

JF - Journal of Vacuum Science and Technology. Part B. Microelectronics and Nanometer Structures

SN - 1071-1023

IS - 6

M1 - 062001

ER -