Self-aligned quadruple patterning integration using spacer on spacer pitch splitting at the resist level for sub-32nm pitch applications

Raley, Angélique; Thibaut, Sophie; Mohanty, Nihar; Kal, Subhadeep; Nakamura, Satoru; Ko, Akiteru; O'Meara, David; Tapily, Kandabara; Consiglio, Steven; Biolsi, Peter

doi:10.1117/12.2219321

Cited by 19 publications

(9 citation statements)

References 3 publications

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“…Atomic layer deposition (ALD) is a well-established technique used for the synthesis of ultrathin conformal films with atomic-level thickness control. , This high level of conformality and thickness control is enabled by the self-limiting nature of the alternated precursor and coreactant steps. Plasma-assisted ALD, in which plasma is used as the coreactant, has further extended the capabilities of ALD, for instance, in terms of low-temperature processing and the number of materials deposited by ALD. , Examples of materials that have received notable interest are TiN and TaN as metal electrode and diffusion barriers, respectively, SiO 2 and TiO 2 as spacer materials for self-aligned patterning, , and HfO 2 as a high- k dielectric . In particular, the usage of SiO 2 in self-aligned multiple patterning has led to the breakthrough of plasma ALD in high-volume manufacturing. , For this application, plasma ALD enables the growth of SiO 2 at low temperature while providing the required high level of film conformality.…”

Section: Introductionmentioning

confidence: 99%

“…Plasma-assisted ALD, in which plasma is used as the coreactant, has further extended the capabilities of ALD, for instance, in terms of lowtemperature processing and the number of materials deposited by ALD. 3,4 Examples of materials that have received notable interest are TiN and TaN as metal electrode and diffusion barriers, respectively, 5 SiO 2 and TiO 2 as spacer materials for self-aligned patterning, 6,7 and HfO 2 as a high-k dielectric. 8 In particular, the usage of SiO 2 in self-aligned multiple patterning has led to the breakthrough of plasma ALD in high-volume manufacturing.…”

Section: ■ Introductionmentioning

confidence: 99%

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Film Conformality and Extracted Recombination Probabilities of O Atoms during Plasma-Assisted Atomic Layer Deposition of SiO₂, TiO₂, Al₂O₃, and HfO₂

et al. 2019

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Surface recombination of plasma radicals is generally considered to limit film conformality during plasma-assisted atomic layer deposition (ALD). Here, we experimentally studied film penetration into high-aspect-ratio structures and demonstrated that it can give direct information on the recombination probability r of plasma radicals on the growth surface. This is shown for recombination of oxygen (O) atoms on SiO2, TiO2, Al2O3, and HfO2 where a strong material dependence has been observed. Using extended plasma exposures, films of SiO2 and TiO2 penetrated extremely deep up to an aspect ratio (AR) of ∼900, and similar surface recombination probabilities of r = (6 ± 2) × 10–5 and (7 ± 4) × 10–5 were determined for these processes. Growth of Al2O3 and HfO2 was conformal up to depths corresponding to ARs of ∼80 and ∼40, with r estimated at (1–10) × 10–3 and (0.1–10) × 10–2, respectively. Such quantitative insight into surface recombination, as provided by our method, is essential for modeling radical-surface interaction and understanding for which materials and conditions conformal film growth is feasible by plasma-assisted ALD.

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Section: Introductionmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

Film Conformality and Extracted Recombination Probabilities of O Atoms during Plasma-Assisted Atomic Layer Deposition of SiO₂, TiO₂, Al₂O₃, and HfO₂

et al. 2019

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“…Examples of such applications include spacers in dynamic random access memory devices, charge trap layers in 3D-NAND flash devices, gate spacers in FinFETs, and chemical–mechanical polishing (CMP) stoppers in a self-aligned multiple patterning process when forming fins in FinFET devices . Using SiN x in the aforementioned applications requires high bulk film density > 2.9 g/cm 3 , excellent film conformality (>95%), and a low process temperature (<400 °C). − Since SiN x serves as both etch stopper and gate spacer in self-aligned multiple patterning for the purpose of narrowing the feature size of fins, − achieving a low wet etch rate (WER) is critical to its successful incorporation into FinFET processing: as an etch stopper, the SiN x pad must be unscathed during subsequent diluted hydrofluoric acid (DHF) cleaning that is done after removing the top mandrel, , while low process temperature is strongly beneficial to prevent any lateral dopant diffusion into the Si-fin body from implanted source and drain dopants if it were used as gate spacer. , …”

Section: Introductionmentioning

confidence: 99%

Investigation of the Physical Properties of Plasma Enhanced Atomic Layer Deposited Silicon Nitride as Etch Stopper

Kim

Meng

Kim

et al. 2018

ACS Appl. Mater. Interfaces

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Correlations between physical properties linking film quality with wet etch rate (WER), one of the leading figures of merit, in plasma-enhanced atomic layer deposition (PEALD) grown silicon nitride (SiN x ) films remain largely unresearched. Achieving a low WER of a SiN x film is especially significant in its use as an etch stopper for technology beyond 7 nm node semiconductor processing. Herein, we explore the correlation between the hydrogen concentration, hydrogen bonding states, bulk film density, residual impurity concentration, and the WERs of PEALD SiN x using Fourier transform infrared spectrometry, X-ray reflectivity, and spectroscopic ellipsometry, etc. PEALD SiN x films for this study were deposited using hexachlorodisilane and hollow cathode plasma source under a range of process temperatures (270–360 °C) and plasma gas compositions (N2/NH3 or Ar/NH3) to understand the influence of hydrogen concentration, hydrogen bonding states, bulk film density, and residual impurity concentration on the WER. Varying hydrogen concentration and differences in the hydrogen bonding states resulted in different bulk film densities and, accordingly, a variation in WER. We observe a linear relationship between hydrogen bonding concentration and WER as well as a reciprocal relationship between bulk film density and WER. Analogous to the PECVD SiN x processes, a reduction in hydrogen bonding concentration arises from either (1) thermal activation or (2) plasma excited species. However, unlike the case with silane (SiH4)-based PECVD SiN x , PEALD SiN x WERs are affected by residual impurities of Si precursors (i.e., chlorine impurity). Thus, possible wet etching mechanisms in HF in which the WER is affected by hydrogen bonding states or residual impurities are proposed. The shifts of amine basicity in SiN x due to different hydrogen bonding states and the changes in Si electrophilicity due to Cl impurity content are suggested as the main mechanisms that influence WER in the PEALD processes.

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“…Dense lines and space patterns are initially formed by SAQP, and then multiple cuts or trim masks with very fine isolated features are used to cut the lines into useful device features or wiring. 9,10 The EPE is a function of the critical dimension (CD) variation as well as the pattern overlay (OL) error for each mask. 11…”

Section: Processes For Patterning and Overlay Controlmentioning

confidence: 99%

Perspective: New process technologies required for future devices and scaling

Clark¹,

Tapily²,

Yu³

et al. 2018

APL Materials

143

179

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This paper presents an overview and perspective on processing technologies required for continued scaling of leading edge and emerging semiconductor devices. We introduce the main drivers and trends affecting future semiconductor device scaling and provide examples of emerging devices and architectures that may be implemented within the next 10-20 yr. We summarize multiple active areas of research to explain how future thin film deposition, etch, and patterning technologies can enable 3D (vertical) power, performance, area, and cost scaling. Emerging and new process technologies will be required to enable improved contacts, scaled and future devices and interconnects, monolithic 3D integration, and new computing architectures. These process technologies are explained and discussed with a focus on opportunities for continued improvement and innovation.

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Self-aligned quadruple patterning integration using spacer on spacer pitch splitting at the resist level for sub-32nm pitch applications

Cited by 19 publications

References 3 publications

Film Conformality and Extracted Recombination Probabilities of O Atoms during Plasma-Assisted Atomic Layer Deposition of SiO₂, TiO₂, Al₂O₃, and HfO₂

Film Conformality and Extracted Recombination Probabilities of O Atoms during Plasma-Assisted Atomic Layer Deposition of SiO₂, TiO₂, Al₂O₃, and HfO₂

Investigation of the Physical Properties of Plasma Enhanced Atomic Layer Deposited Silicon Nitride as Etch Stopper

Perspective: New process technologies required for future devices and scaling

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Self-aligned quadruple patterning integration using spacer on spacer pitch splitting at the resist level for sub-32nm pitch applications

Cited by 19 publications

References 3 publications

Film Conformality and Extracted Recombination Probabilities of O Atoms during Plasma-Assisted Atomic Layer Deposition of SiO2, TiO2, Al2O3, and HfO2

Film Conformality and Extracted Recombination Probabilities of O Atoms during Plasma-Assisted Atomic Layer Deposition of SiO2, TiO2, Al2O3, and HfO2

Investigation of the Physical Properties of Plasma Enhanced Atomic Layer Deposited Silicon Nitride as Etch Stopper

Perspective: New process technologies required for future devices and scaling

Contact Info

Product

Resources

About

Film Conformality and Extracted Recombination Probabilities of O Atoms during Plasma-Assisted Atomic Layer Deposition of SiO₂, TiO₂, Al₂O₃, and HfO₂

Film Conformality and Extracted Recombination Probabilities of O Atoms during Plasma-Assisted Atomic Layer Deposition of SiO₂, TiO₂, Al₂O₃, and HfO₂