Wataru Shibayama

Approach to hp10nm resolution by applying Dry Development Rinse Process (DDRP) and Materials (DDRM)

EUV lithography has been desired as the leading technology for single nm half-pitch patterning. However, the source power, masks and resist materials still have critical issues for mass production. Especially in resist materials, RLS trade-off is the key issue. To overcome this issue, we are suggesting Dry Development Rinse Process (DDRP) and Materials (DDRM) as the pattern collapse mitigation approach. This DDRM can perform not only as pattern collapse free materials for fine pitch, but also as the etching hard mask against bottom layer (spin on carbon : SOC). In this paper, we especially propose new approaches to achieve high resolution around hp10nm. The key points of our concepts are 1) control PR profiles, 2) new solvent system to avoid chemical mixture, 3) high etching selective DDR materilas and 4) high planar DDR materials. This new DDRM technology can be the promising approach for hp10nm level patterning in N7/N5 and beyond.

EUV sensitive Si containing hard mask (Si-HM) for PTD and NTD process in EUVL

Tri-layer process is the one of the key technique both for the lithography and etching around Hp20nm patterning. In applying for tri-layer process, we are focusing on inorganic type under layer which mainly containing Si atoms. This Si type hard mask (Si-HM) can perform not only as the Lithography performance enhancement layer for fine pitch, but also as the etching hard mask against bottom layer (spin on carbon : SOC). In this paper, we propose our new Si-HM concepts to achieve high sensitivity, wide process window and good line edge roughness. The key point of our concepts is EUV sensitive unit in Si-HM. Our EUV sensitive unit strongly promotes acid generation from PAG of EUV photo resist. Especially, for EUV NTD lithography process, EUV sensitive unit can perform as the adhesion enhancer between Si-HM and photo resist at EUV exposed area. As this result, we could resolve 22nm L/S=1/1 pattern on the EUV sensitive Si-HM by EUV NTD process even in the condition which hp40nm was the resolution limit with HMDS treated Bare-Si / PR stack. Moreover, from the view point of etching hard mask, 30nm dense L/S pattern and 20nm semi iso line pattern could be transferred to SOC layer successfully. We will present our latest Si-HM performance specialized for EUV lithography.

Novel ArF extension technique by applying Dry Development Rinse Process (DDRP) and Materials (DDRM)

ArF lithography is still major process to develop N7/N5 devices. Especially in resist materials, DOF, roughness and CD uniformity are the biggest key parameters in fine pitches. To improve these issues, we newly propose to apply Dry Development Rinse Process (DDRP) and Materials (DDRM) as the ArF extension approach. In EUV lithography, DDRP is already one of the approaches to achieve high resolution. However, the performance of DDRP for ArF lithography was never demonstrated in detail. In this paper, we especially focus to improve DOF, CD uniformity and roughness by applying DDRP for ArF generation. Finally we succeeded to enhance every parameter at the same time by controlling DDRM etching condition. This new DDRP technology can be the promising approach for ArF extension stages in N7/N5 and beyond.

EUV lithography and etching performance enhancement by EUV sensitive Si hard mask (EUV Si-HM) for 1Xnm hp generation

Tri-layer process is the one of the key technique both for lithography and etching around Hp20nm patterning. In applying for tri-layer process, we are focusing on inorganic type under layer which mainly containing Si atoms. This Si type hard mask (Si-HM) can perform not only as the Lithography performance enhancement layer for fine pitch, but also as the etching hard mask against bottom layer (spin on carbon : SOC). In this paper, we propose our new Si-HM concepts to achieve high sensitivity, wide process window and good line edge roughness for hp 1Xnm generation. The key point of our concepts is EUV sensitive unit in Si-HM. Our EUV sensitive unit strongly promotes acid generation from PAG of EUV photo resist. Especially, for EUV NTD lithography process, EUV sensitive unit can perform as the adhesion enhancer between Si-HM and photo resist at EUV exposed area. As this result, hp18nm L/S pattern and hp24nm C/H pattern were successfully achieved by applying the EUV sensitive Si-HM in EUV PTD process. Especially, as compared to organic UL, the 4th generation EUV sensitive Si-HM showed 5~10% higher sensitivity and 10~25% wider process window (DOF and EL) with keeping LER. Moreover this EUV-sensitive Si-HM could also enhance the ultimate resolution to Hp22nm L/S in EUV NTD process. On the other hand, from the view point of etching hard mask, around hp 19 nm Si-HM L/S pattern could be transferred to SOC layer successfully. We will present the high resolution concepts and performances of our latest EUV sensitive Si-HM for 1X nm generation in EUV lithography.

Novel DDR process and materials for front-edge NTD process

We developed the novel process and material which can prevent the pattern collapse issue perfectly. The process was Dry Development Rinse (DDR) process, and the material used in this process was DDR Material (DDRM). DDRM was containing siloxane polymer which could be replaced the space area of the photo resist pattern. And finally, the reversed pattern would be created by dry etching process without any pattern collapse issue. This novel process was useful not only in positive tone development (PTD) process but also in negative tone development (NTD) process. We newly developed DDRM for NTD process. Novel DDRM consist of special polymer and it used organic solvent system. So, new DDRM showed no mixing property with NTD photo resist and it has enough etch selectivity against NTD photo resist. Image reversal was successfully achieved by combination of NTD process and DDR process keeping good pattern quality. Tone reverse pattern below hp 18nm was obtained without any pattern collapse issue, which couldn’t be created by just using normal NTD process.

Advanced development of organic and inorganic under layers for EUV lithography (Conference Presentation)

EUV lithography has been desired as the leading technology for below Hp20nm. However, the source power, masks and resist materials still have critical issues for mass production. Especially in resist materials, RLS trade-off is the key issue. To overcome this issue, we are focusing on Organic & Inorganic Hard Mask as the bottom layer of EUV PR. Especially, Inorganic under layers (Si-HM) can perform not only as the lithographic performance enhancement layer for fine pitch, but also as the etching hard mask against bottom layer (spin on carbon : SOC). In this paper, we especially propose new approaches to achieve high resolution below hp16nm. The key points of our concepts are EUV-sensitive units of Si-HM. This new EUV sensitive Si-HM could resolve Hp14nm L/S pattern with wide DOF margin. It can also perform as the high universal materials in any development process (PTD & NTD) and any PR materials. Moreover, the latest Organic under layers developed for the advanced EUV CAR PR & Metal resist also will be discussed in the paper. From the Organic & Inorganic under layer material design, we will present new concepts to get high resolution in EUVL.

DDR process and materials for novel tone reverse technique

We developed the novel process and material which can be created reverse-tone pattern without any collapse. The process was Dry Development Rinse (DDR) process, and the material used in this process was DDR material. DDR material was containing siloxane polymer which could be replaced the space area of the photo resist pattern. And finally, the reverse-tone pattern could be obtained by dry etching process without any pattern collapse issue. DDR process could be achieved fine line and space patterning below hp14nm without any pattern collapse by combination of PTD or NTD photo resist. DDR materials were demonstrated with latest coater track at imec. DDR process was fully automated and good CD uniformity was achieved after dry development. Detailed evaluation could be achieved with whole wafer such a study of CD uniformity (CDU). CDU of DDR pattern was compared to pre-pattern’s CDU. Lower CDU was achieved and CDU healing was observed with special DDR material. By further evaluation, special DDR material showed relatively small E-slope compared to another DDR material. This small E-slope caused CDU improvement.

DDR process and materials for NTD photo resist toward 1Xnm patterning and beyond

We developed the novel process and material which can prevent the pattern collapse issue perfectly. The process was Dry Development Rinse (DDR) process, and the material used in this process was DDR material. DDR materials were containing siloxane polymer which could be replaced the space area of the photo resist pattern. And finally, the reversed pattern would be created by dry etching process without any pattern collapse issue.

Single-nm resolution approach by applying DDRP and DDRM

EUV lithography has been desired as the leading technology for 1x or single nm half-pitch patterning. However, the source power, masks and resist materials still have critical issues for mass production. Especially in resist materials, RLS trade-off has been the key issue. To overcome this issue, we are suggesting Dry Development Rinse Process (DDRP) and Materials (DDRM) as the pattern collapse mitigation approach. This DDRM can perform not only as pattern collapse free materials for fine pitch, but also as the etching hard mask against bottom layer (spin on carbon : SOC). In this paper, we especially propose new approaches to achieve high resolution around hp1X nm L/S and single nm line patterning. Especially, semi iso 8nm line was successfully achieved with good LWR (2.5nm) and around 3 times aspect ratio. This single nm patterning technique also helped to enhance sensitivity about 33%. On the other hand, pillar patterning thorough CH pattern by applying DDRP also showed high resolution below 20nm pillar CD with good LCDU and high sensitivity. This new DDRP technology can be the promising approach not only for hp1Xnm level patterning but also single nm patterning in N7/N5 and beyond.

DDR process and materials for NTD photo resist in EUV lithography

We developed the novel process and material which can prevent the pattern collapse issue perfectly. The process was Dry Development Rinse (DDR) process, and the material used in this process was DDR material. DDR material was containing siloxane polymer which could be replaced the space area of the photo resist pattern. And finally, the reversed pattern would be created by dry etching process without any pattern collapse issue. This novel process was useful not only in positive tone development (PTD) process but also in negative tone development (NTD) process. We newly developed DDR material for NTD process. Novel DDR material for NTD consists of special polymer and it used organic solvent system. New DDR materials showed no mixing property for NTD PR, so fine pattern of NTD PR could be filled by DDR materials then tone reverse could be achieved by dry etching process. Tone reverse was successfully achieved by combination of NTD PR and DDR process keeping good pattern quality in EUV lithography. Reversed pattern below hp 14nm was obtained without any pattern collapse issue, which couldn’t be created by just using normal NTD process. Reversed contact hole could be obtained in NTD-DDR process at 24nm hole size. Reversed C/H made by NTD pillar showed good LCDU compared to PTD C/H. In addition, reversed C/H at 20nm hole size could be achieved in NTD-DDR process. In DDR process, enough etch back is important to obtained fine reversed pattern with lower roughness but long etch back time caused degradation of the reversed pattern. Then etch back time was evaluated with NTD PR and DDR material. Reversed C/H showed minimum LCDU when short etch back time was applied, however degradation of LCDU was observed when long etch back was applied. LCDU of reversed C/H made by NTD-DDR process was 3.2nm. On the other hands, LCDU of normal C/H made by PTD process was 3.5nm, so reversed C/H from NTD pillar showed better LCDU than PTD C/H when suitable etch back was applied.