Chlorine based focused electron beam induced etching: A novel way to pattern germanium

Abstract

a b s t r a c tFocused electron beam induced etching (FEBIE) with chlorine as etching agent has been used to geometrically shape and to electrically modify semiconductor nanodevices. Selected sections of monocrystalline nanowires were modified directly without the requirement for a photomask or a resist layer. FEBIE as a subtractive nanofabrication technology allows to locally etch active semiconductor devices made of Si or Ge. In this work, chlorine is used as the etchant gas to thin germanium channel structures fabricated by standard photolithography. For effective material removal a sufficiently high electron influence is essential to avoid the pitfalls of this method. Topography and conductivity of FEBIE-modified structures prior and after the etching process was studied by AFM and by electrical I-V characteristics. The presented work demonstrates the potential of Cl-based FEBIE for device prototyping and electrical trimming of future Ge-based nanodevices.

Nanoscale Ruthenium-Containing Deposits from Ru(CO)4I2via Simultaneous Focused Electron Beam-Induced Deposition and Etching in Ultrahigh Vacuum: Mask Repair in Extreme Ultraviolet Lithography and Beyond

“…In previously published papers, FEBIE was extensively studied, and it was proposed that halogen ligands can cause an etching process by forming the volatile byproduct under the influence of an electron beam. While the existing studies mainly focused on XeF 2 as the precursor gas on different substrate materials, − dichloride was also reported to etch a germanium substrate in the presence of an electron beam . The conditions specified in the literature for successful FEBIE correspond to those used in our study, namely, a low hydrocarbon level in the chamber, along with a focused low-energy high-current electron beam, and short or long dwell times depending on the systems. , Also, in the latter works, the underlying mechanism to trigger FEBIE has been claimed to be the electron-induced decomposition of SiO 2 into Si. , During this process, electron-stimulated desorption of O from the surface creates active sites such as O vacancies. , Based on the acquired data, the exact mechanism for simultaneous etching/FEBIE and deposition/FEBID must remain speculative.…”

“…While the existing studies mainly focused on XeF2 as precursor gas on different substrate materials, [55][56][57][58] also Cl2 was reported to etch a Ge substrate in the presence of an electron beam. 59 The conditions specified in literature for successful FEBIE correspond to those used in our study, namely a low hydrocarbon level in the chamber, along with a focused low-energy high-current electron beam, and short or long dwell times depending on the systems. [58][59] Moreover, the studies combining FEBIE and FEBID typically used two different precursor sources, one for FEBID and one for FEBIE.…”

“…59 The conditions specified in literature for successful FEBIE correspond to those used in our study, namely a low hydrocarbon level in the chamber, along with a focused low-energy high-current electron beam, and short or long dwell times depending on the systems. [58][59] Moreover, the studies combining FEBIE and FEBID typically used two different precursor sources, one for FEBID and one for FEBIE. The advantage of simultaneous FEBID and FEBIE is an increased metal content of deposited material.…”

Patterning of diamond with 10 nm resolution by electron-beam-induced etching

“…As a less-destructive patterning technique of diamond layers, gas-assisted electron-beam induced etching (EBIE) [14,15] was proposed, which is a well-known technique being used for high resolution patterning of semiconductors such as GaAs [16] and Ge [17] as well as graphene [18]. Gasassisted EBIE to pattern diamond was first proposed by Taniguchi et al [19] and we show here that is an alternative, low-damage method that opens the way for mask-less Original content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence.…”