Silicon nitride nanotemplate fabrication using inductively coupled plasma etching process

Abstract

In this work, we have investigated the fabrication of ordered silicon nitride nanohole arrays as part of an overall process aimed at producing organized silicon nanocrystals. The authors have demonstrated that it is possible to use inductively coupled plasma etching systems in order to etch nanometric layers, despite the fact that these systems are designed for deep and fast etching. A stable process is developed for shallow etching of silicon nitride nanoholes. The influence of different plasma etching parameters on silicon nitride nanohole properties is analyzed. 30 nm deep nanoholes of approximately 30 nm diameter, near vertical sidewalls and a good control of the selectivity are achieved. The overall process provides a simple and reproducible approach based on shallow inductively coupled plasma etching to obtain high quality nanosized silicon nitride templates. A suitable process for organized arrays of 10 nm diameter silicon nanocrystals realized by electrochemical etching is shown.

E‐H Transition in Argon/Oxygen Inductively Coupled RF Plasmas

“…Inductively coupled radio frequency (RF) discharges (ICP) enable a wide range of applications and attracted an increasing interest so that they have been gained importance for plasma processing applications [1], e.g., in semiconductor industry and for light source technology [2]. ICPs are more recently being used for plasma etching [3][4][5][6][7][8][9][10][11], sterilization and decontamination of sensitive material surfaces [12][13][14], particle generation [15,16], growth of carbon nano tubes [17], polymerization [18], diamond deposition [19,20] surface modification [21] and vapor deposition [22]. Additionally, ICPs are also used in life science [23], for atomic clocks for the global positioning system (GPS) [24] and they are used for thrusters in electric propulsion [25].…”

Inductively coupled plasma etching of ultra-shallow Si3N4 nanostructures using SF6/C4F8 chemistry

“…The etch rates decrease with the coil power. Dissociation and ionization of C 4 F 8 , SF 6 and their by-products decrease when coil power is lowered [21]. Due to the decrease of the fluxes of both neutrals and ions, silicon nitride and ZEP etching are impaired.…”

“…For Si 3 N 4 plasma etching, fluorine gases such as CH 3 F [8], CF 4 [9], SF 6 [10] and NF 3 [11] are mixed with O 2 , N 2 , H 2 or NO in order to get a high anisotropy and a high selectivity over SiO 2 and Si. Fluorine species can react with Si 3 N 4 to form volatile SiF 4 compounds whereas fluorocarbon polymer deposition on surface inhibits the etching of silicon nitride [12].…”

“…In the fabrication of nanodevices, controllable slow etch rates are more and more demanded for the etching of thin films. For instance, the etching of ultra-shallow nanostructures is required in the fabrication of nanoscale templates for silicon nanocrystals [6] or in the nanodamascene process for single electron transistors (SET) fabrication [7].…”

Etching Characteristics and Mechanism of SiN<SUB><I>x</I></SUB> Films for Nano-Devices in CH<SUB>2</SUB>F<SUB>2</SUB>/O<SUB>2</SUB>/Ar Inductively Coupled Plasma: Effect of O<SUB>2</SUB> Mixing Ratio

“…The commonly used methods are the low pressure chemical vapor deposition (LPCVD) and the plasma enhanced chemical vapor deposition (PECVD). 10 Similarly to SiO 2 , the dry etching of silicon nitride films is provided by the fluorine-based gas chemistries, [11][12][13][14][15][16][17][18][19] mostly by the CF 4 -based plasmas. The majority of published works reported about the etching characteristics and mechanisms for the stoichiometric Si 3 N 4 films (produced by the LPCVD method) in the plate-parallel reactive ion etching (RIE) systems.…”