Yosuke Shirata

High-productivity immersion scanner enabling 1xnm hp manufacturing

NSR-S622D, Nikon’s new ArF immersion scanner, provides the best and practicable solutions to meet the escalating requirement from device manufactures to accommodate the further miniaturization of device pattern. NSR-S622D has various additional functions compared to the previous model such as the newly developed illumination system, new projection lens, new AF system new wafer table in addition to the matured Streamlign platform. These new features will derive the outstanding performance of NSR, enabling highly controlled CD uniformity, focus accuracy and overlay accuracy. NSR-S622D will provide the adequate capabilities that are demanded from a lithography tool for production of 1x nm hp node and beyond.

Latest performance of ArF immersion scanner NSR-S630D for high-volume manufacturing for 7nm node

In order to achieve stable operation in cutting-edge semiconductor manufacturing, Nikon has developed NSR-S630D with extremely accurate overlay while maintaining throughput in various conditions resembling a real production environment. In addition, NSR-S630D has been equipped with enhanced capabilities to maintain long-term overlay stability and user interface improvement all due to our newly developed application software platform. In this paper, we describe the most recent S630D performance in various conditions similar to real productions. In a production environment, superior overlay accuracy with high dose conditions and high throughput are often required; therefore, we have performed several experiments with high dose conditions to demonstrate NSR’s thermal aberration capabilities in order to achieve world class overlay performance. Furthermore, we will introduce our new software that enables long term overlay performance.

Stability and calibration of overlay and focus control for a double patterning immersion scanner

To achieve the 2 nm overlay accuracy required for double patterning, we have introduced the NSR-S620D immersion scanner that employs an encoder metrology system. The key challenges for an encoder metrology system include its stability as well as the methods of calibration. The S620D has a hybrid metrology system consisting of encoders and interferometers, in XY and Z. The advantage of a hybrid metrology system is that we can continuously monitor the position of the stage using both encoders and interferometers for optimal positioning control, without any additional metrology requirements or throughput loss. To support this technology, the S620D has various encoder calibration functions that make and maintain the ideal grid, and control focus. In this paper we will introduce some of the encoder calibration functions based on the interferometer. We also provide the latest performance of the tool, with an emphasis on overlay and focus control, validating that the NSR-S620D delivers the necessary levels of accuracy and stability for the production phase of double patterning.

Double patterning lithography study with high overlay accuracy

Double patterning (DP) has become the most likely candidate to extend immersion lithography to the 32 nm node and beyond. This paper focuses on experimental results of 32nm half pitch patterning using NSR-S620D, the latest Nikon ArF immersion scanner. A litho-freeze-litho (LFL) process was employed for this experiment. Experimental results of line CDU, space CDU, and overlay accuracy are presented. Finally, a budget for pitch splitting DP at the 22 nm half pitch is presented.

An immersion scanner enabling 10 nm half pitch production and high productivity

Nikons newly developed immersion scanner, NSR-S630D, provides exceptional performance in product overlay, CD uniformity, and productivity at 10 nm hp node and beyond. Generally, maintaining machine accuracy and productivity at a high level is difficult because they are in a trade-off relationship. The NSR-S630D is equipped with new features including an encoder servo-controlled reticle stage, reticle bending mechanism, optics with enhanced thermal aberration control, and thermally stable wafer stage. These features enable the NSR-S630D to deliver highest accuracy and productivity.

Immersion scanners enabling 10nm half-pitch production and beyond

Nikon’s new immersion scanner “NSR-S630D” has been developed to deliver enhanced product overlay and CD uniformity while improving productivity at 10 nm half pitch node and beyond. The NSR-S630D is equipped with various advanced technologies. Among them are the new reticle stage with encoder servo control and advanced reticle bending mechanism, new optics with enhanced correction knobs for thermal aberration control, and advanced thermally stable wafer stage; all of which are key components to providing the best scanner solution to meet the requirements for 10 nm half pitch node and beyond. In this paper, we describe the NSR-630D development concept and the latest performance data at factory. One of the key factors in improving overlay is shot distortion; in order to improve shot distortion, the NSR-S630D is equipped with a newly developed state-of-the-art projection lens. The overall overlay improvements have been made possible not only by minimizing lens distortion through advancements in lens manufacturing techniques, but also by reducing thermal distortion, which is especially important in actual device production. In addition, we have also added a new function for more effective reticle heating distortion compensation. In order to improve wafer grid performance, we newly designed a wafer table with enhanced thermal stability. We have also further improved the reticle bending system in order to minimize the field curvature induced by projection lens thermal aberration. The new features described above, in addition to the matured Streamlign platform, have enabled the NSR-S630D to deliver highest accuracy and stability.