Pulsed high-density plasmas for advanced dry etching processes

Banna, S.; Agarwal, Ankur; Cunge, G.; Darnon, Maxime; Pargon, E.; Joubert, O.

doi:10.1116/1.4716176

Cited by 161 publications

(110 citation statements)

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“…54 Already in today's advanced RIE etching, we witness the steady development of advanced pulsed waveform plasma etching to meet the stringent requirements for further nanoelectronics scaling beyond the 10-nm technology node by better control of the critical plasma parameters such as ion and radical densities, ion energy distribution functions, 38,39 and electron temperature in conventional high-density plasma reactors. 55 We conclude that today the potential of ALD-assisted nanomanufacturing technologies like Atomic Layer Etching (ALEt) concepts derived from etch-purge-passivation/deposition-purge subroutines in (D)RIE and ALD is now clearly being recognized and promoted. 10,54,56,[57][58][59] The ongoing scaling of Moore's Law will soon require the implemention of these complementary technologies to meet the 10-nm challenges in surface and sidewall passivation of resist and feature patterns that is required to minimize interface, line edge and fin wall roughness.…”

Section: Concluding Remarks and Outlookmentioning

confidence: 99%

Cyclic Etch/Passivation-Deposition as an All-Spatial Concept toward High-Rate Room Temperature Atomic Layer Etching

Roozeboom

Bruele

Creyghton

et al. 2015

ECS J. Solid State Sci. Technol.

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Conventional (3D) etching in silicon is often based on the 'Bosch' plasma etch with alternating half-cycles of a directional Sietch and a fluorocarbon polymer passivation. Also shallow feature etching is often based on cycled processing. Likewise, ALD is time-multiplexed, with the extra benefit of half-reactions being self-limiting, thus enabling layer-by-layer growth in a cyclic process. To speed up growth rate, spatial ALD has been successfully commercialized for large-scale and high-rate deposition at atmospheric pressure. We conceived a similar spatially-divided etch concept for (high-rate) Atomic Layer Etching (ALEt). The process is converted from time-divided into spatially-divided by inserting inert gas-bearing 'curtains' that confine the reactive gases to individual injection slots in a gas injector head. By reciprocating substrates back and forth under such head one can realize the alternate etching/passivation-deposition cycles at optimized local pressures, without idle times needed for switching pressure or purging. Another improvement toward an all-spatial approach is the use of ALD-based oxide (Al 2 O 3 , SiO 2 , etc.) as passivation during, or gap-fill after etching. This approach, called spatial ALD-enabled RIE, has industrial potential in cost-effective back-endof-line and front-end-of-line processing, especially in patterning structures requiring minimum interface, line edge and fin sidewall roughness (i.e., atomic-scale fidelity with selective removal of atoms and retention of sharp corners). Today, the continuous doubling of the transistor count on planar microprocessor and memory chips in a two-year cadence has reached the point where Moore's Law (essentially an economic law) and Dennard's scaling (transistor and pitch dimensions) have approached their limits in 2D-scaling. The end of the planar device era was marked with the introduction in 2011 of the 22-nm Tri-Gate device.1,2 Figure 1 shows its design with gates surrounding the channel on three sides of vertical fins to improve gate delay.Today, at the emergence of the 10-nm technology node and the 50 th anniversary of Moore's Law, 3D device and integration solutions are being rapidly introduced both intra-chip, e.g., Gate-All-Around, 3 vertical NAND, 4 and inter-chip, e.g., 3D Through-Silicon Vias (TSVs). 5History of 3D etching.-Whereas the transistor design has been planar for most of its history, its periphery has been subjected to 3D design early on. One of the earliest 3D concepts has been the basic invention of 3D TSVs, already filed in 1958 by the famous W. Shockley, 6 cf. Fig. 2. Yet, in reality 3D Through-Silicon Via (TSV) technology took decades to accelerate the now rapidly growing stacked-chips and micro-electromechanical systems (MEMS) markets by enabling their interconnection in a 3D-integrated System-in-Package (i.e. the so-called 'More than Moore' domain). Today, the mainstream industrial technology for etching of both TSV and MEMS structures is ion-assisted etching or (Deep) Reactive Ion Etching. This method has become so ...

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Section: Concluding Remarks and Outlookmentioning

confidence: 99%

Cyclic Etch/Passivation-Deposition as an All-Spatial Concept toward High-Rate Room Temperature Atomic Layer Etching

Roozeboom

Bruele

Creyghton

et al. 2015

ECS J. Solid State Sci. Technol.

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“…[3][4][5][6] An alternative and possibly complementary approach corresponds to the reverse of atomic layer deposition technology.…”

Section: Technology Demands On Plasma Etch (Pe) and Key Shortcomings mentioning

confidence: 99%

“…[1][2][3][4][5][6][7][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.…”

mentioning

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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“…In this case, when the bias power is turned off suddenly, it will induce enough reacting before the back potential force forms. This kind of time-split to bias on/off results smaller depth loading effect that are caused by different opening CD size [122,123]. (a) (b) It is possible to fine-tune the gas ratio and bias power to improve the Ion/Neutral flux ratio and improve the CD size dependency to etch rate.…”

Section: Depth Loading Control Of Fin Etchingmentioning

confidence: 99%

The Challenges of Advanced CMOS Process from 2D to 3D

Radamson

Zhang

et al. 2017

Applied Sciences

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Abstract:The architecture, size and density of metal oxide field effect transistors (MOSFETs) as unit bricks in integrated circuits (ICs) have constantly changed during the past five decades. The driving force for such scientific and technological development is to reduce the production price, power consumption and faster carrier transport in the transistor channel. Therefore, many challenges and difficulties have been merged in the processing of transistors which have to be dealed and solved. This article highlights the transition from 2D planar MOSFETs to 3D fin field effective transistors (FinFETs) and then presents how the process flow faces different technological challenges. The discussions contain nano-scaled patterning and process issues related to gate and (source/drain) S/D formation as well as integration of III-V materials for high carrier mobility in channel for future FinFETs.

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Pulsed high-density plasmas for advanced dry etching processes

Cited by 161 publications

References 110 publications

Cyclic Etch/Passivation-Deposition as an All-Spatial Concept toward High-Rate Room Temperature Atomic Layer Etching

Cyclic Etch/Passivation-Deposition as an All-Spatial Concept toward High-Rate Room Temperature Atomic Layer Etching

Atomic Layer Etching at the Tipping Point: An Overview

The Challenges of Advanced CMOS Process from 2D to 3D

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