Dry Etching Technology for Semiconductors

Abstract

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Overview of atomic layer etching in the semiconductor industry

“…2(a), to maintain critical dimension of the mask. 12,13 The most extensively used process is reactive ion etching (RIE), which is a type of (dry) plasma etching involving a partially ionized plasma glow discharge that provides a mixture of reactive and nonreactive ions, electrons, reactive neutrals, passivating species, and photons. Directionality for positively charged ions is provided by accelerating them normal to the wafer surface through a negative voltage bias on the wafer substrate.…”

“…33 However, plasma chlorination considerably increases the possibility of background etching due to the presence of radicals, ions, photons, metastables, and low energy electrons, all of which can potentially induce etching. 13 Photons may play a role, as they are known to induce subthreshold etching as described by Shin et al 100 Low energy ions should not etch at subthreshold energies (<16 eV), although molecular dynamic simulations by Brichon et al show a finite silicon etching yield for chlorine ions with kinetic energies as low as 5 eV. 20 Even "nonreactive" species in plasma such as He neutrals can deliver substantial (>10 eV) energy through relaxation of Rydberg states.…”

Optical Emission Spectroscopic (OES) analysis for diagnostics of electron density and temperature in non-equilibrium argon plasma based on collisional-radiative model

“…microelectronics, semiconductors, material engineering, etc., where low-pressure discharge plasmas have been utilized for a long time with practical levels of industry. For example, in the microelectronics engineering, dry etching processes have been widely applied for more than 30 years for the commercial fabrication of memories [7], where typically, fluorine radicals are generated from fluorocarbon gases in the argon-based low-temperature plasmas like CCP [8,9], ICP [10,11], ECR plasmas [12,13], or others, and applied to material etching out of the substrate. On the other hand, for thin-film deposition processes like photovoltaic-device manufacturing, silicon-based materials are quite often deposited on substrates from the SiH 4 or other siliconcompound gaseous molecules [14,15].…”

mCharacteristics of Carbon Tetrafluoride Plasma Resistance of Various Glasses

“…2, a schematic diagram for plasma reaction and etching process occurring in the material is summarized. 17) In the etching with the use of plasma, particles ionized by granting electrical energy in the state of neutral gas are used. And, by granting electrical energy to CF 4 , O 2 and Ar neutral gas, the ionization processes can be shown approximately by the equations (1), (2) and 3, respectively.…”