CMP 패드 두께 프로파일 측정 장치 및 방법에 관한 연구 = A Study on CMP Pad Thickness Profile Measuring Device and Method

다국어 초록 (Multilingual Abstract)

The chemical mechanical planarization (CMP) is a process of physically and chemically polishing the semiconductor substrate. The planarization quality of a substrate can be evaluated by the within wafer non-uniformity (WIWNU). In order to improve WIWNU, it is important to manage the pad profile. In this study, a device capable of non-contact measurement of the pad thickness profile was developed. From the measured pad profile, the profile of the pad surface and the groove was extracted using the envelope function, and the pad thickness profile was derived using the difference between each profile. Thickness profiles of various CMP pads were measured using the developed PMS and envelope function. In the case of IC series pads, regardless of the pad wear amount, the envelopes closely follow the pad surface and grooves, making it easy to calculate the pad thickness profile. In the case of the H80 series pad, the pad thickness profile was easy to derive because the pad with a small wear amount did not reveal deep pores on the pad surface. However, the pad with a large wear amount make errors in the lower envelope profile, because there are pores deeper than the grooves. By removing these deep pores through filtering, the pad flatness could be clearly confirmed. Through the developed PMS and the pad thickness profile calculation method using the envelope function, the pad life, the amount of wear and the pad flatness can be easily derived and used for various pad analysis.

참고문헌 (Reference)

1 K., Zhai, "Study on Chemical Mechanical Polishing of Silicon Wafer with Megasonic Vibration Assisted" 80 : 9-14, 2017

2 J. H. Oh, "Stres s Dis tribution on the Wafer according to Pad Profile" 363-364, 2008

3 Jr, C. R. Johnson, "Software receiver design: build your own digital communication system in five easy steps" Cambridge University Press 416-417, 2011

4 A. S. Lawing, "Pad Conditioning for Poromeric Materials" 2017

5 L. Shan, "Mechanical Interactions and Their Effects on Chemical Mechanical Polishing" 14 (14): 207-213, 2001

6 O. Chang, "Mathematical Modeling of CMP Conditioning Process" 84 (84): 577-583, 2007

7 T. Sun, "Inves tigating t he E ffect o f Diamond Size and Conditioning Force on Chemical Mechanical Planarization Pad Topography" 87 (87): 553-559, 2010

8 이우진, "Enhancement of CMP pad lifetime for shallow trench isolation process using profile simulation" 한국물리학회 9 (9): 134-137, 2009

9 Z. C. Li, "Diamond Disc Pad Conditioning in Chemical Mechanical Planarization(CMP) : a Surface Element Method to Predict Pad Surface Shape" 36 (36): 356-363, 2012

10 J. M. Steigerwald, "Chemical Processes in the Chemical Mechanical Polishing of Copper" 41 (41): 217-228, 1995

11 박기원, "CMP용 리테이닝 링의 재질이 웨이퍼의 연마성능에 미치는 영향" 한국기계가공학회 19 (19): 22-28, 2020

12 이동환, "CMP 컨디셔너의 다이아몬드 입자 모양이 연마 패드 표면 형상 제어에 미치는 영향" 한국트라이볼로지학회 35 (35): 330-336, 2019

13 J. H. Lee, "A Study on the Characteristics of Electro Polishing and Utility Materials for Transit High Purity Gas" 7 (7): 259-263, 2004

14 S. H. Lee, "A Study on Novel Conditioning for CMP" 16 (16): 40-47, 1999