Measurement of oxide etch rate of SOI structure using near IR microscopy

Research output: Contribution to journalArticleScientificpeer-review

1 Citation (Scopus)

Abstract

The sacrificial oxide etching is one of the key steps in fabrication of micromechanical devices on bonded silicon on insulator (SOI) wafers.
The determination of the etch rate of buried oxide layers in bonded SOI wafers from scanning electron microscopy (SEM) cross-sections is a rather tedious and time consuming task. However, the knowledge of the etch front propagation is essential for ensuring the success of etch release and thus the device operation. In this paper a fast and non-destructive method for measurement of sacrificial oxide layer etch rates is described.
The pattern and time dependencies of SOI structure etching in concentrated hydrofluoric acid are studied by near infrared microscopy. The etch length of the SOI can be accurately measured with IR microscope. The measurement results were also verified by SEM cross-sections.
The observed variation in etch rates can be explained by the SOI interface quality and not by any aspect ratio dependency caused by varying structure layer thickness. In the used etch times for etching of the thermal oxide the etch-rate seems to be limited by the bonded interface quality and not by transport limitations.
The results of these experiments and some application examples are shown. Other possible applications, limitations and error sources of this method are discussed.
Original languageEnglish
Pages (from-to)185-187
JournalPhysica Scripta
Volume2002
Issue numberT101
DOIs
Publication statusPublished - 2002
MoE publication typeA1 Journal article-refereed
Event19th Nordic Semiconductor Meeting, NSM19
- Copenhagen, Denmark
Duration: 20 May 200123 May 2001

Fingerprint

Silicon-on-insulator
Microscopy
Oxides
insulators
microscopy
Etching
oxides
silicon
etching
Scanning Electron Microscopy
Wafer
Cross section
wafers
Front Propagation
scanning electron microscopy
cross sections
hydrofluoric acid
Aspect Ratio
Microscope
aspect ratio

Cite this

@article{31a7ae7f344d41ffaf50bd73fe76e937,
title = "Measurement of oxide etch rate of SOI structure using near IR microscopy",
abstract = "The sacrificial oxide etching is one of the key steps in fabrication of micromechanical devices on bonded silicon on insulator (SOI) wafers. The determination of the etch rate of buried oxide layers in bonded SOI wafers from scanning electron microscopy (SEM) cross-sections is a rather tedious and time consuming task. However, the knowledge of the etch front propagation is essential for ensuring the success of etch release and thus the device operation. In this paper a fast and non-destructive method for measurement of sacrificial oxide layer etch rates is described. The pattern and time dependencies of SOI structure etching in concentrated hydrofluoric acid are studied by near infrared microscopy. The etch length of the SOI can be accurately measured with IR microscope. The measurement results were also verified by SEM cross-sections. The observed variation in etch rates can be explained by the SOI interface quality and not by any aspect ratio dependency caused by varying structure layer thickness. In the used etch times for etching of the thermal oxide the etch-rate seems to be limited by the bonded interface quality and not by transport limitations. The results of these experiments and some application examples are shown. Other possible applications, limitations and error sources of this method are discussed.",
author = "Jyrki Kiiham{\"a}ki",
year = "2002",
doi = "10.1238/Physica.Topical.101a00185",
language = "English",
volume = "2002",
pages = "185--187",
journal = "Physica Scripta",
issn = "0031-8949",
publisher = "Institute of Physics IOP",
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}

Measurement of oxide etch rate of SOI structure using near IR microscopy. / Kiihamäki, Jyrki.

In: Physica Scripta, Vol. 2002, No. T101, 2002, p. 185-187.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Measurement of oxide etch rate of SOI structure using near IR microscopy

AU - Kiihamäki, Jyrki

PY - 2002

Y1 - 2002

N2 - The sacrificial oxide etching is one of the key steps in fabrication of micromechanical devices on bonded silicon on insulator (SOI) wafers. The determination of the etch rate of buried oxide layers in bonded SOI wafers from scanning electron microscopy (SEM) cross-sections is a rather tedious and time consuming task. However, the knowledge of the etch front propagation is essential for ensuring the success of etch release and thus the device operation. In this paper a fast and non-destructive method for measurement of sacrificial oxide layer etch rates is described. The pattern and time dependencies of SOI structure etching in concentrated hydrofluoric acid are studied by near infrared microscopy. The etch length of the SOI can be accurately measured with IR microscope. The measurement results were also verified by SEM cross-sections. The observed variation in etch rates can be explained by the SOI interface quality and not by any aspect ratio dependency caused by varying structure layer thickness. In the used etch times for etching of the thermal oxide the etch-rate seems to be limited by the bonded interface quality and not by transport limitations. The results of these experiments and some application examples are shown. Other possible applications, limitations and error sources of this method are discussed.

AB - The sacrificial oxide etching is one of the key steps in fabrication of micromechanical devices on bonded silicon on insulator (SOI) wafers. The determination of the etch rate of buried oxide layers in bonded SOI wafers from scanning electron microscopy (SEM) cross-sections is a rather tedious and time consuming task. However, the knowledge of the etch front propagation is essential for ensuring the success of etch release and thus the device operation. In this paper a fast and non-destructive method for measurement of sacrificial oxide layer etch rates is described. The pattern and time dependencies of SOI structure etching in concentrated hydrofluoric acid are studied by near infrared microscopy. The etch length of the SOI can be accurately measured with IR microscope. The measurement results were also verified by SEM cross-sections. The observed variation in etch rates can be explained by the SOI interface quality and not by any aspect ratio dependency caused by varying structure layer thickness. In the used etch times for etching of the thermal oxide the etch-rate seems to be limited by the bonded interface quality and not by transport limitations. The results of these experiments and some application examples are shown. Other possible applications, limitations and error sources of this method are discussed.

U2 - 10.1238/Physica.Topical.101a00185

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JO - Physica Scripta

JF - Physica Scripta

SN - 0031-8949

IS - T101

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