Dr. Alok Ranjan Profile

Dr. Alok Ranjan

Director at Tokyo Electron Miyagi Ltd

SPIE Involvement:

Author

Publications (9)

Proceedings Article | 20 March 2019 Paper

Peculiarities of selective isotropic Si etch to SiGe for nanowire and GAA transistors

Christopher Catano, Nicholas Joy, Christopher Talone, Shyam Sridhar, Sergey Voronin, Peter Biolsi, Alok Ranjan

Proceedings Volume 10963, 109630E (2019) https://doi.org/10.1117/12.2514566

KEYWORDS: Silicon, Etching, Germanium, Plasmas, Interfaces, Isotropic etching, Nanowires, Transistors, 3D applications

Read Abstract +

Proceedings Article | 20 March 2019 Open Access

Etch aware computational patterning in the era of atomic precision processing

P. L. Ventzek, J. Shinagawa, A. Ranjan

Proceedings Volume 10963, 1096304 (2019) https://doi.org/10.1117/12.2513211

KEYWORDS: Etching, Plasma, Optical lithography, Photomasks, Plasma etching, Chemistry, Monte Carlo methods, Ions, Lithography, Silicon

Read Abstract +

DOWNLOAD PAPER

Proceedings Article | 20 March 2018 Paper

Selective dry etching of silicon containing anti-reflective coating

Shyam Sridhar, Andrew Nolan, Li Wang, Erdinc Karakas, Sergey Voronin, Peter Biolsi, Alok Ranjan

Proceedings Volume 10589, 1058908 (2018) https://doi.org/10.1117/12.2297418

KEYWORDS: Etching, Plasmas, Dry etching, Oxides, Oxygen, Plasma treatment

Read Abstract +

Multi-layer patterning schemes involve the use of Silicon containing Anti-Reflective Coating (SiARC) films for their anti-reflective properties. Patterning transfer completion requires complete and selective removal of SiARC which is very difficult due to its high silicon content (>40%). Typically, SiARC removal is accomplished through a non-selective etch during the pattern transfer process using fluorine containing plasmas, or an ex-situ wet etch process using hydrofluoric acid is employed to remove the residual SiARC, post pattern transfer. Using a non-selective etch may result in profile distortion or wiggling, due to distortion of the underlying organic layer. The drawbacks of using wet etch process for SiARC removal are increased overall processing time and the need for additional equipment. Many applications may involve patterning of active structures in a poly-Si layer with an underlying oxide stopping layer. In such applications, SiARC removal selective to oxide using a wet process may prove futile. Removing SiARC selectively to SiO₂ using a dry etch process is also challenging, due to similarity in the nature of chemical bonds (Si – O) in the two materials.

In this work, we present highly selective etching of SiARC, in a plasma driven by a surface wave radial line slot antenna. The first step in the process involves an in-situ modification of the SiARC layer in O2 plasma followed by selective etching in a NF₃/H₂ plasma. Surface treatment in O₂ plasma resulted in enhanced etching of the SiARC layer. For the right processing conditions, in-situ NF₃/H₂ dry etch process demonstrated selectivity values greater than 15:1 with respect to SiO₂. The etching chemistry, however, was sensitive to NF₃:H₂ gas ratio. For dilute NF₃ in H₂, no SiARC etching was observed. Presumably, this is due to the deposition of ammonium fluorosilicate layer that occurs for dilute NF₃/H₂ plasmas. Additionally, challenges involved in selective SiARC removal (selective to SiO2, organic and Si layers) post pattern transfer, in a multi-layer structure will be discussed.

Proceedings Article | 20 March 2018 Presentation + Paper

New frontiers of atomic layer etching

Sonam Sherpa, Alok Ranjan

Proceedings Volume 10589, 1058909 (2018) https://doi.org/10.1117/12.2284662

KEYWORDS: Silicon, Etching, Plasma, Hydrogen, Ions, Ion beams, Oxides, Fluorine

Read Abstract +

Proceedings Article | 21 March 2017 Paper

Guiding gate-etch process development using 3D surface reaction modeling for 7nm and beyond

Derren Dunn, John Sporre, Vaibhav Deshpande, Mohamed Oulmane, Ronald Gull, Peter Ventzek, Alok Ranjan

Proceedings Volume 10149, 101490Q (2017) https://doi.org/10.1117/12.2271389

KEYWORDS: Etching, Process modeling, Ions, Image processing, Oxides, Monte Carlo methods, 3D modeling, Plasma etching, Chemical elements, Interfaces, Optical lithography, Plasma, Bromine, Semiconducting wafers

Read Abstract +

Proceedings Article | 23 March 2016 Paper

Plasma etch patterning of EUV lithography: balancing roughness and selectivity trade off

Vinayak Rastogi, Genevieve Beique, Lei Sun, Hongyun Cottle, Yannick Feurprier, Andrew Metz, Kaushik Kumar, Cathy Labelle, John Arnold, Matthew Colburn, Alok Ranjan

Proceedings Volume 9782, 97820B (2016) https://doi.org/10.1117/12.2216840

KEYWORDS: Line edge roughness, Line width roughness, Plasma etching, Plasma, Etching, Optical lithography, Extreme ultraviolet, Photoresist processing, Extreme ultraviolet lithography, Lithography, Materials processing, Ions, Chemistry

Read Abstract +

Proceedings Article | 17 March 2015 Paper

Challenges and mitigation strategies for resist trim etch in resist-mandrel based SAQP integration scheme

Nihar Mohanty, Elliott Franke, Eric Liu, Angelique Raley, Jeffrey Smith, Richard Farrell, Mingmei Wang, Kiyohito Ito, Sanjana Das, Akiteru Ko, Kaushik Kumar, Alok Ranjan, David O'Meara, Kenjiro Nawa, Steven Scheer, Anton DeVillers, Peter Biolsi

Proceedings Volume 9428, 94280G (2015) https://doi.org/10.1117/12.2085016

KEYWORDS: Etching, Optical lithography, Lithography, Plasma etching, Vacuum ultraviolet, Line edge roughness, Plasma, Semiconducting wafers, Line width roughness, Photomasks

Read Abstract +

Proceedings Article | 17 March 2015 Paper

Electron energy distribution control by fiat: breaking from the conventional flux ratio scaling rules in etch

Alok Ranjan, Mingmei Wang, Sonam Sherpa, Peter Ventzek

Proceedings Volume 9428, 94280O (2015) https://doi.org/10.1117/12.2086604

KEYWORDS: Ions, Etching, Plasma, Chemistry, Microwave radiation, Silicon, Adsorption, Semiconducting wafers, Plasma generation, Tellurium

Read Abstract +

Proceedings Article | 22 March 2008 Paper

Advanced profile control and the impact of sidewall angle at gate etch for critical nodes

Hyung Lee, Alok Ranjan, Dan Prager, Kenneth Bandy, Eric Meyette, Radha Sundararajan, Anita Viswanathan, Asao Yamashita, Merritt Funk

Proceedings Volume 6922, 69220T (2008) https://doi.org/10.1117/12.774962

KEYWORDS: Etching, Critical dimension metrology, Control systems, Semiconducting wafers, Process control, Scatterometry, Metrology, Diffractive optical elements, Mathematical modeling, Oxygen

Read Abstract +

Showing 5 of 9 publications

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Keywords/Phrases

Search In:

Publication Years