Selective etching of TiN over TaN and vice versa in chlorine-containing plasmas

Abstract

Articles you may be interested inDifferences in erosion mechanism and selectivity between Ti and TiN in fluorocarbon plasmas for dielectric etch Selectivity of etching between physical vapor-deposited TiN and TaN was studied in chlorinecontaining plasmas, under isotropic etching conditions. Etching rates for blanket films were measured in-situ using optical emission of the N 2 (C 3 P u !B 3 P g ) bandhead at 337 nm to determine the etching time, and transmission electron microscopy to determine the starting film thickness. The etching selectivity in Cl 2 /He or HCl/He plasmas was poor (<2:1). There was a window of very high selectivity of etching TiN over TaN by adding small amounts (<1%) of O 2 in the Cl 2 /He plasma. Reverse selectivity (10:1 of TaN etching over TiN) was observed when adding small amounts of O 2 to the HCl/He plasma. Results are explained on the basis of the volatility of plausible reaction products.

A current driven capacitively coupled chlorine discharge

“…The electronegative molecular chlorine discharge is widely used in plasma etching of semiconductors and metals [1]. Recently, chlorine-containing plasmas have been found to achieve selective etching of high-k materials over silicon-based substrates [2] and TiN over TaN and vice versa [3]. The application of chlorine plasmas in manufacturing integrated circuits has been comprehensively reviewed recently by Donnelly and Kornblit [4].…”

Three-terminal nanoelectromechanical switch based on tungsten nitride—an amorphous metallic material

“…We developed a reactive ion etching process using chlorine (Cl 2 ) and oxygen (O 2 ) plasma, to pattern the amorphous WN x thin film. These gases were chosen since tungsten is known to form volatile oxychloride compounds (WO x Cl y ) [26], while nitrogen can be emitted as nitrogen gas (N 2 ) [27]. Furthermore, since this etch chemistry is selective to WN x over silicon oxide (SiO 2 ) by 15:1, it is amenable to the use of a SiO 2 hard mask for highaspect-ratio etching.…”

Influence of C2F6Addition to Cl2/Ar Gas on Nanometer-Scale Etch Characteristics of TiN Thin Films Using Inductively Coupled Plasma

“…[1][2][3][4] In the past, some etching studies on TiN thin films have been performed using Cl 2 , BCl 3 , HBr, NF 3 , CF 4 , and SF 6 gases. [5][6][7][8][9][10][11][12][13] On the other hand, there are few reports on the etching process of nanometer-sized TiN films.…”