Infinitely high etch selectivity during CH2F2/H2 dual-frequency capacitively coupled plasma etching of silicon nitride to chemical vapor-deposited a-C

Kim, J. S.; Kwon, B. S.; Heo, W.; Jung, Changho; Park, J. S.; Shon, J. W.; Lee, Nae‐Eung

doi:10.1116/1.3430551

Cited by 6 publications

(4 citation statements)

References 17 publications

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“…[3][4][5][6] or hydrofluorocarbon C x H y F z (Refs. [7][8][9][10][11][12][13][14][15] chemistries. Fluorine-rich gases such as CF 4 , C 4 F 8 , or CHF 3 with a high Si 3 N 4 etch rate of about 30 nm min −1 were investigated.…”

Section: Introductionmentioning

confidence: 99%

Gate spacers etching of Si3N4 using cyclic approach for 3D CMOS devices

Bacquié

Tavernier

Boulard

et al. 2021

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

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In this work, we optimize a CH 3 F/O 2 /He/SiCl 4 chemistry to etch silicon nitride gate spacers for 3D CMOS devices in a 300 mm inductively coupled plasma reactor. The chemistry has high directivity and high selectivity to Si and SiO 2 . A cyclic approach, which alternates this chemistry with a CH 2 F 2 /O 2 /CH 4 /He plasma, is investigated. Using quasi in situ x-ray photoelectron spectroscopy and ellipsometry measurements, etching mechanisms are proposed to explain the results obtained. As a result of process optimization, silicon nitride spacers with vertical profile and a small critical dimension loss of 3 nm as well as complete spacers removal on sidewalls of the active area are obtained on 3D patterns, confirming the advantages of this approach.

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Section: Introductionmentioning

confidence: 99%

Gate spacers etching of Si3N4 using cyclic approach for 3D CMOS devices

Bacquié

Tavernier

Boulard

et al. 2021

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

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“…As the device structure becomes complicated for high performance and high integrity, we should have more precisely controlled SiN etching technology. [1][2][3][4][5][6][7][8][9][10][11] Silicon nitride is frequently used for gate spacers and gate caps, as shown in Fig. 1.…”

Section: Introductionmentioning

confidence: 99%

SiN etching characteristics of Ar/CH₃F/O₂ plasma and dependence on SiN film density

Ohtake¹,

Wanifuchi

Sasaki

2016

Jpn. J. Appl. Phys.

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We evaluated the silicon nitride (SiN) etching characteristics of Ar/O2/hydrofluorocarbon plasma. Ar/CH3F/O2 plasma achieved a high etching selectivity of SiN to SiO2 by increasing the oxygen flow rate. We also evaluated the dependence of SiN etching characteristics on SiN film density. A low-density film deposited at a low temperature of 200 °C (by plasma-enhanced CVD, PECVD) showed an 8–20% lower etching rate of SiN than a high-density film deposited at a high temperature of 780 °C (by low-pressure CVD, LPCVD) when we had a low RF bias of 30 W. This PECVD film might move the competitive balance to oxidation from fluorination, reducing the SiN etching rate. However, when we have a high RF bias of more than 50 W, the SiN etching rate is 2–15% higher in the PECVD film than in the LPCVD film. The etching rate of SiN at various densities depends on the balance between oxidation and ion bombardment.

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“…High etching selectivity between the stressed SiN and its oxide stop layer is also required. [ 3,4,5] In this work, we investigated the etching selectivity behavior between nitride and oxide in the above mentioned two typical etch processes. Results indicate the desired selectivity could not be achieved without the appropriate etcher.…”

Section: Iintroductionmentioning

confidence: 99%

Highly Selective Etching Solutions for Advanced Logic Technologies

et al. 2011

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As logic semiconductor moves to 65nm node and beyond, several process-enhancement technologies have come into prominence with the help of dry etch processes. In high-aspect ratio contact etch (CT) process, the sufficient over-etch during dielectric oxide etch without too much loss of SiN-based stop layer is required to maintain the enough process window for less silicide loss loading and leakage. Stress memorization technology (SMT) is designed to enhance the P-MOS performance. It removes the stressed nitride and stops on one thin oxide layer. The enough oxide remaining is also imperative to avoid silicon damage. Besides, the loading effect of nitride thickness in SRAM area has to be compensated. Highly selective etching process is indispensable to fulfill these tightening and newly-born process requirements. In this paper, we address the effect of etch parameters including pressure, chemistry, gas ratio and power on the etching selectivity between nitride and oxide film in the above two processes. Scanning Electron Microscope (SEM) is utilized to compare the final etched profile. Results demonstrate besides the etch chemistry and power ratio, the etcher selection also plays the vital role on etching selectivity and etch rate.

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Infinitely high etch selectivity during CH2F2/H2 dual-frequency capacitively coupled plasma etching of silicon nitride to chemical vapor-deposited a-C

Cited by 6 publications

References 17 publications

Gate spacers etching of Si3N4 using cyclic approach for 3D CMOS devices

Gate spacers etching of Si3N4 using cyclic approach for 3D CMOS devices

SiN etching characteristics of Ar/CH₃F/O₂ plasma and dependence on SiN film density

Highly Selective Etching Solutions for Advanced Logic Technologies

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Infinitely high etch selectivity during CH2F2/H2 dual-frequency capacitively coupled plasma etching of silicon nitride to chemical vapor-deposited a-C

Cited by 6 publications

References 17 publications

Gate spacers etching of Si3N4 using cyclic approach for 3D CMOS devices

Gate spacers etching of Si3N4 using cyclic approach for 3D CMOS devices

SiN etching characteristics of Ar/CH3F/O2 plasma and dependence on SiN film density

Highly Selective Etching Solutions for Advanced Logic Technologies

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SiN etching characteristics of Ar/CH₃F/O₂ plasma and dependence on SiN film density