Ion-enhanced chemical etching of ZrO2 in a chlorine discharge

Abstract

Origin and effect of impurity incorporation in plasma-enhanced ZrO 2 deposition J. Appl. Phys. 93, 9345 (2003); 10.1063/1.1572193Fluorinated-chlorinated SiO 2 films prepared at low temperature by remote plasma-enhanced chemical-vapor deposition using mixtures of SiF 4 and SiCl 4Chlorine plasma is found to chemically etch ZrO 2 thin films in an electron cyclotron resonance reactor, and the etch rate scaled linearly with the square root of ion energy at high ion energies with a threshold energy between 12-20 eV. The etching rate decreased monotonically with increasing chamber pressures, which corresponds to reduced electron temperatures. Optical emission spectroscopy and quadrupole mass spectrometry were used to identify the reaction etching products. No Zr, O, or ZrCl were detected as etching products, but highly chlorinated zirconium compounds ͑ZrCl 2 , ZrCl 3, and ZrCl 4 ͒ and ClO were found to be the dominant etching products. ZrCl 3 was the dominant etching products at low ion energies, while ZrCl 4 became dominant at higher ion energies. This is consistent with greater momentum transfer and enhanced surface chlorination, as determined by x-ray photoelectron spectroscopy, at increased ion energies. Several ion-enhanced chemical reactions are proposed to contribute to the ZrO 2 etching.

Selective Etching of High-kDielectric HfO2Films over Si in BCl3-Containing Plasmas without rf Biasing

“…1,2) For the integration of high-k dielectric materials in device fabrication, highly selective etching over underlying Si is indispensable for their removal prior to forming source and drain contacts. Plasma etching of high-k dielectrics has used not only chlorine-based gases such as Cl 2 , 3,4) BCl 3 , [5][6][7][8] BCl 3 / Cl 2 , [5][6][7][8] and Cl 2 /HBr, 9,10) but also fluorine-based gases such as SF 6 , 4) CF 4 , 9,10) and CHF 3 . 10,11) However, the etch selectivity for high-k/Si was not so high (often up to 3 -5), due to the highly volatile halogen compounds of Si, and also to the strong metal-oxygen bonds of high-k dielectrics and less volatile metal-halogen compounds.…”

Surface Etching of TiO2Thin Films Using High Density Cl2/Ar Plasma

“…Generally, the combination of Cl 2 and Ar enhances the etch rate of metal-oxide materials by forming volatile etch by-products, such as ClO x and metal-chlorides. Otherwise, the etch rate is decreased by forming non-volatile etch by-products of ClO [9][10]. If Cl 2 O 3 is accumulated on the surface, this layer precludes any chemical reactions between Cl and metals [11].…”

Feature profile evolution during shallow trench isolation etching in chlorine-based plasmas. III. The effect of oxygen addition

“…17 The plasma was sustained and controlled using a WAVEMAT MPDR TM 325i microwave plasma source with an ASTeX S-1500 power generator at 2.45 GHz. 17 The plasma was sustained and controlled using a WAVEMAT MPDR TM 325i microwave plasma source with an ASTeX S-1500 power generator at 2.45 GHz.…”

“…17,18 An Ocean Optics TM USB-4000 OES with five optical channels covering the wavelength range from 200 to 1000 nm was used to obtain the relative number density of the reactive species including Cl and O. The Langmuir probe was a Hiden Analytical TM ESPION electrostatic model with a tungsten tip of 0.15 mm diameter and 3 mm length.…”