Advances in Patterning Materials and Processes at SPIE Advanced Lithography

February 20,2017

We are again looking forward to taking part in the SPIE Advanced Lithography Conference in San Jose, California. This year’s event takes place February 26-March 2, 2017 at the San Jose Marriott and San Jose Convention Center.

With a more than 40-year history, SPIE Advanced Lithography draws industry leaders from around the globe to share the latest developments in lithography and patterning. If you are attending this year’s conference, be sure to mark your program for two sessions from Dow experts as part of the Advances in Patterning Materials and Processes conference. Brief summaries of the presentations follow.

Embedded Top-Coat for Reducing the Effect of Out of Band Radiation in EUV Lithography
Tuesday, February 28, 9:00am
Session 5 – EUV Materials III: Fundamentals II
Peter Trefonas and James W. Thackeray, Dow Electronic Materials
In collaboration with Andrew Whittaker, Idriss Blakey, Ke Du, Meiliana Siauw and David Valade from The University of Queensland

In order for extreme ultraviolet (EUV) lithography to enter production, several challenges must be addressed. For example, out-of-band (OOB) photons emitted by the EUV source along with the desired EUV wavelengths can significantly deteriorate lithographic patterning performance. While conventional EUV photoresists have evolved from materials designed for lithography at 193 nm and 248 nm, the wavelength of out-of-band radiation is generally from 150~400 nm. Hence if OOB light generated from plasma source reaches the wafer plane, and the resist is sensitive to that light, then contrast and line edge roughness will be reduced, resulting in degraded imaging performance [1, 2].

This study examines some recent work into the design of an OOB protection layer (OBPL) or topcoat, and performance requirements for such a material. The presentation will describe the design of a surface-active polymer, which is able to undergo phase segregation from a photoresist matrix to form a topcoat. The investigation addresses the variety of surface agents (fluorinated, hydrocarbon, etc.) and quantity required to provide the most effective phase separation from the photoresist.

Advanced Hole Patterning Technology using Soft Spacer Materials
Thursday, March 2, 10:50am
Session 14 – Process Integration and Multipatterning
Jong Keun Park, Phillip D. Hustad, Emad Aqad, David Valeri, Mike Wagner and Mingqi Li, Dow Electronic Materials

A continuing goal in the integrated circuit industry is to increase density of features within patterned masks. One pathway being used by the device manufacturers for patterning beyond the ~80nm pitch limitation of 193 immersion lithography is the self-aligned spacer double patterning (SADP). Two orthogonal line space patterns with subsequent SADP can be used for contact holes multiplication. However, a combination of two immersion exposures, two spacer deposition processes, and two etch processes to reach the desired dimensions makes this process expensive and complicated.

One alternative technique for contact hole multiplication is the use of an array of pillar patterns. Pillars, imaged with 193 immersion photolithography, can be uniformly deposited with spacer materials until a hole is formed in the center of four pillars. Selective removal of the pillar core gives a reversal of phases, a contact hole where there was once a pillar. However, due to the highly conformal nature of conventional spacer materials, the new holes formed by this method have a tendency to be imperfect and not circular.

This presentation will address the use of both conventional spacer material and soft spacer materials to improve contact hole circularity. Application of soft spacer materials can be achieved by an existing coating track without additional cost burden to the device manufacturers.

To see the full technical program, spanning seven conferences, visit the SPIE Advanced Lithography website.

If you’d like to meet with someone from Dow at SPIE Advanced Lithography to discuss our lithography solutions or research, please reach out to your account representative or contact us to schedule a meeting. We hope to connect with you at the conference!

 


  
  

References:
1. Koji Inukai, S.S., Hiroki Nakagawa, Makoto Shimizu, Toru Kimura, Effects of Out of Band Radiation on EUV Resist Performance. Proc. of SPIE, 2012. 8322.
2. Jeanette M. Roberts, R.L.B., Todd R. Younkin, Theodore H. Fedynyshyn, David K. and a.A.C. Astolfi, Sensitivity of EUV resists to out-of-band radiation. Proc. of SPIE, 2009. 7273: p. 72731W-1.

We are again looking forward to taking part in the SPIE Advanced Lithography Conference in San Jose, California. This year’s event takes place February 26-March 2, 2017 at the San Jose Marriott and San Jose Convention Center.

With a more than 40-year history, SPIE Advanced Lithography draws industry leaders from around the globe to share the latest developments in lithography and patterning. If you are attending this year’s conference, be sure to mark your program for two sessions from Dow experts as part of the Advances in Patterning Materials and Processes conference. Brief summaries of the presentations follow.

Embedded Top-Coat for Reducing the Effect of Out of Band Radiation in EUV Lithography
Tuesday, February 28, 9:00am
Session 5 – EUV Materials III: Fundamentals II
Peter Trefonas and James W. Thackeray, Dow Electronic Materials
In collaboration with Andrew Whittaker, Idriss Blakey, Ke Du, Meiliana Siauw and David Valade from The University of Queensland

In order for extreme ultraviolet (EUV) lithography to enter production, several challenges must be addressed. For example, out-of-band (OOB) photons emitted by the EUV source along with the desired EUV wavelengths can significantly deteriorate lithographic patterning performance. While conventional EUV photoresists have evolved from materials designed for lithography at 193 nm and 248 nm, the wavelength of out-of-band radiation is generally from 150~400 nm. Hence if OOB light generated from plasma source reaches the wafer plane, and the resist is sensitive to that light, then contrast and line edge roughness will be reduced, resulting in degraded imaging performance [1, 2].

This study examines some recent work into the design of an OOB protection layer (OBPL) or topcoat, and performance requirements for such a material. The presentation will describe the design of a surface-active polymer, which is able to undergo phase segregation from a photoresist matrix to form a topcoat. The investigation addresses the variety of surface agents (fluorinated, hydrocarbon, etc.) and quantity required to provide the most effective phase separation from the photoresist.

Advanced Hole Patterning Technology using Soft Spacer Materials
Thursday, March 2, 10:50am
Session 14 – Process Integration and Multipatterning
Jong Keun Park, Phillip D. Hustad, Emad Aqad, David Valeri, Mike Wagner and Mingqi Li, Dow Electronic Materials

A continuing goal in the integrated circuit industry is to increase density of features within patterned masks. One pathway being used by the device manufacturers for patterning beyond the ~80nm pitch limitation of 193 immersion lithography is the self-aligned spacer double patterning (SADP). Two orthogonal line space patterns with subsequent SADP can be used for contact holes multiplication. However, a combination of two immersion exposures, two spacer deposition processes, and two etch processes to reach the desired dimensions makes this process expensive and complicated.

One alternative technique for contact hole multiplication is the use of an array of pillar patterns. Pillars, imaged with 193 immersion photolithography, can be uniformly deposited with spacer materials until a hole is formed in the center of four pillars. Selective removal of the pillar core gives a reversal of phases, a contact hole where there was once a pillar. However, due to the highly conformal nature of conventional spacer materials, the new holes formed by this method have a tendency to be imperfect and not circular.

This presentation will address the use of both conventional spacer material and soft spacer materials to improve contact hole circularity. Application of soft spacer materials can be achieved by an existing coating track without additional cost burden to the device manufacturers.

To see the full technical program, spanning seven conferences, visit the SPIE Advanced Lithography website.

If you’d like to meet with someone from Dow at SPIE Advanced Lithography to discuss our lithography solutions or research, please reach out to your account representative or contact us to schedule a meeting. We hope to connect with you at the conference!

 


  
  

References:
1. Koji Inukai, S.S., Hiroki Nakagawa, Makoto Shimizu, Toru Kimura, Effects of Out of Band Radiation on EUV Resist Performance. Proc. of SPIE, 2012. 8322.
2. Jeanette M. Roberts, R.L.B., Todd R. Younkin, Theodore H. Fedynyshyn, David K. and a.A.C. Astolfi, Sensitivity of EUV resists to out-of-band radiation. Proc. of SPIE, 2009. 7273: p. 72731W-1.