Understanding time-resolved processes in atomic-layer etching of ultra-thin Al2O3 film using BCl3 and Ar neutral beam

Jhon, Young In; Min, K. S.; Yeom, Geun‐Young; Jhon, Young Min

doi:10.1063/1.4894523

Cited by 12 publications

(15 citation statements)

References 25 publications

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“…27,28,29 The weakened Cladsorbed MoS 2 top layer was physically desorbed by the ion bombardment from a lowenergy Ar + ion beam during the desorption step. The Ar + ion bombardment not only breaks the Mo-S binding in the layer, but also removes the broken MoS-Cl/S-Cl from the MoS 2 surface.…”

Section: Resultsmentioning

confidence: 99%

Controlled Layer-by-Layer Etching of MoS₂

Lin

Kang

Jeon

et al. 2015

ACS Appl. Mater. Interfaces

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Two-dimensional (2-D) metal dichalcogenides like molybdenum disulfide (MoS 2 ) may provide a pathway to high-mobility channel materials that are needed for beyondcomplementary metal-oxide-semiconductor (CMOS) devices. Controlling the thickness of these materials at the atomic level will be a key factor in the future development of MoS 2 devices. In this study, we propose a layer-by-layer removal of MoS 2 using the atomic layer etching (ALET) that is composed of the cyclic processing of chlorine (Cl)-radical adsorption and argon (Ar) + ion-beam desorption. MoS 2 etching was not observed with only the Clradical adsorption or low-energy (< 20 eV) Ar + ion-beam desorption steps; however, the use of sequential etching that is composed of the Cl-radical adsorption step and a subsequent Ar + ion-beam desorption step resulted in the complete etching of one monolayer MoS 2 . Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM) indicated the removal of one monolayer MoS 2 with each ALET cycle; therefore, the number of MoS 2 layers could be precisely controlled by using this cyclical etch method. In addition, no noticeable damage or etch residue was observed on the exposed MoS 2 .

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Section: Resultsmentioning

confidence: 99%

Controlled Layer-by-Layer Etching of MoS₂

Lin

Kang

Jeon

et al. 2015

ACS Appl. Mater. Interfaces

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“…They also describe results of density functional theory for the interaction of BCl 3 with Al 2 O 3 which they thought provided insights that could be exemplary for other ALE systems as well. 58 For BeO on GaAs negligible sputtering was seen for bombardment energies of less than 130 eV, and a self-limited etch depth of 0.75 Å/cycle at saturation. 43 used exposure of GaAs to Cl 2 gas and electron bombardment at 100 eV to demonstrate a self-limited iterative etching approach.…”

Section: Atomic Layer Etching Of Various Materials -A Brief Surveymentioning

confidence: 99%

Atomic Layer Etching at the Tipping Point: An Overview

Oehrlein

Metzler

2015

ECS J. Solid State Sci. Technol.

232

162

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The ability to achieve near-atomic precision in etching different materials when transferring lithographically defined templates is a requirement of increasing importance for nanoscale structure fabrication in the semiconductor and related industries. The use of ultra-thin gate dielectrics, ultra thin channels, and sub-20 nm film thicknesses in field effect transistors and other devices requires near-atomic scale etching control and selectivity. There is an emerging consensus that as critical dimensions approach the sub-10 nm scale, the need for an etching method corresponding to Atomic Layer Deposition (ALD), i.e. Atomic Layer Etching (ALE), has become essential, and that the more than 30-year quest to complement/replace continuous directional plasma etching (PE) methods for critical applications by a sequence of individual, self-limited surface reaction steps has reached a crucial stage. A key advantage of this approach relative to continuous PE is that it enables optimization of the individual steps with regard to reactant adsorption, self-limited etching, selectivity relative to other materials, and damage of critical surface layers. In this overview we present basic approaches to ALE of materials, discuss similarities/crucial differences relative to thermal and plasma-enhanced ALD, and then review selected results on ALE of materials aimed at pattern transfer. The overview concludes with a discussion of opportunities and challenges ahead. A requirement of increasing importance for nanoscale device fabrication is the ability to achieve atomic scale etching control and materials selectivity during pattern transfer.1-8 An etching method corresponding to Atomic Layer Deposition (ALD), i.e. Atomic Layer Etching (ALE), is expected to satisfy these needs as critical dimensions continue to shrink below the 10 nm scale.Demonstrations of self-limited dry etching methods capable of near-atomic resolution have a long history in the dry etching community and a brief review will be presented below. Key challenges for these approaches have been specialized equipment, long process times and low throughput.9,10 However, a recent demonstration using a commercial plasma etch tool 10 and activities within the dry etching community 11 provide indications that the situation has changed, and that we may have reached for ALE the Tipping Point which Gladwell defined as the "the moment of critical mass, the threshold, the boiling point" when "ideas and products and messages and behaviors spread like viruses do".12 This is due to several factors, including unprecedented demands on dry etching technology introduced by the semiconductor device evolution according to Moore's law that can be satisfied by atomic layer etching, advanced capabilities in plasma etch, and the existence of a critical level of information on plasma etch and ALD methods as applied in the semiconductor fabrication space.In this article we will provide a review of background of these approaches, and focus on issues that have to be overcome for widespread implement...

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“…These include electron cyclotron resonance plasma, 33,39,56,62,86,87 helicon source plasma, 49,88 TCP, 6 capacitively coupled plasma, 5,60,89 and inductively coupled plasma. 90 Other types of energetic species have also been evaluated, including ion beams, 40,48 neutral beams, 35,[50][51][52]68,69,83,[91][92][93][94][95][96] and laser beams. 32,66,67,97,98 While specialized equipment certainly plays an integral part in basic understanding of ALE, it may be more practical to adapt conventional etching equipment for use in ALE.…”

Section: Argon Ion Bombardmentmentioning

confidence: 99%

“…Modeling efforts started in the late 1990s and includes computational techniques such as molecular dynamics, kinetic Monte Carlo simulations, density functional theory, and feature scale simulators. 5,36,95,99,[102][103][104] Experimentally, a variety of self-limiting mechanisms have been investigated as described throughout this section. Illustrations of different modification mechanisms are shown in Fig.…”

Section: Materials Studied By Ale a Overviewmentioning

confidence: 99%

Overview of atomic layer etching in the semiconductor industry

Kanarik¹,

Lill²,

Hudson³

et al. 2015

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

484

372

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Atomic layer etching (ALE) is a technique for removing thin layers of material using sequential reaction steps that are self-limiting. ALE has been studied in the laboratory for more than 25 years. Today, it is being driven by the semiconductor industry as an alternative to continuous etching and is viewed as an essential counterpart to atomic layer deposition. As we enter the era of atomic-scale dimensions, there is need to unify the ALE field through increased effectiveness of collaboration between academia and industry, and to help enable the transition from lab to fab. With this in mind, this article provides defining criteria for ALE, along with clarification of some of the terminology and assumptions of this field. To increase understanding of the process, the mechanistic understanding is described for the silicon ALE case study, including the advantages of plasma-assisted processing. A historical overview spanning more than 25 years is provided for silicon, as well as ALE studies on oxides, III–V compounds, and other materials. Together, these processes encompass a variety of implementations, all following the same ALE principles. While the focus is on directional etching, isotropic ALE is also included. As part of this review, the authors also address the role of power pulsing as a predecessor to ALE and examine the outlook of ALE in the manufacturing of advanced semiconductor devices.

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Understanding time-resolved processes in atomic-layer etching of ultra-thin Al2O3 film using BCl3 and Ar neutral beam

Cited by 12 publications

References 25 publications

Controlled Layer-by-Layer Etching of MoS₂

Controlled Layer-by-Layer Etching of MoS₂

Atomic Layer Etching at the Tipping Point: An Overview

Overview of atomic layer etching in the semiconductor industry

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Understanding time-resolved processes in atomic-layer etching of ultra-thin Al2O3 film using BCl3 and Ar neutral beam

Cited by 12 publications

References 25 publications

Controlled Layer-by-Layer Etching of MoS2

Controlled Layer-by-Layer Etching of MoS2

Atomic Layer Etching at the Tipping Point: An Overview

Overview of atomic layer etching in the semiconductor industry

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Product

Resources

About

Controlled Layer-by-Layer Etching of MoS₂

Controlled Layer-by-Layer Etching of MoS₂