COP 구조에 사용되는 비정질 실리콘의 다파장 레이저 용융 공정에 대한 연구

다국어 초록 (Multilingual Abstract)

With the development of semiconductor manufacturing technology, the scale of semiconductor devices has become smaller, and the bit integration of memory semiconductors has also increased. Recently, a COP structure V-NAND that can store more data than the existing V-NAND has emerged. Laser annealing of amorphous silicon inside the device is emerging as a key process for the fabrication of V-NAND device based on the COP structure. In this study, a thick (400 nm ) amorphous silicon, imitating the amorphous layer separating the cell area from the peri area in the COP structure, was annealed by using a multi wavelength laser source. The surface morphology, roughness, and degree of recrystallization of the annealed samples were investigated by Scanning Electron Microscope (SEM), Atomic force microscope (AFM), Transmission Electron Microscope (TEM), and X-ray diffraction (XRD). And a numerical simulation of the laser anneal process of the a-Si used in V-NAND COP structures is conducted to predict the evolution of the temperature distribution induced by multi-wavelength laser scanning. In particular, the issues of surface temperature and melt duration, which are critical in actual applications of laser melt annealing in relation to semiconductor fabrication, are discussed based on the temperature distribution obtained from the simulation. According to the simulation results, the temperature in a-Si was well over the melting point (1440 K) of the a-Si, which numerically demonstrated full melting of the a-Si layer. Using multi-wavelength beam instead of single wavelength increased the melt duration of the annealed a-Si, which was beneficial for the formation of large grains.

목차 (Table of Contents)

• I. 서 론 1
• 1.1. 연구 배경 및 문헌 조사 1
• 1.1.1) 반도체제조기술 발전에 따른 낸드 플래시 메모리의 발달 1
• 1.1.2) 다양한 어닐 공정의 특징 2
• 1.1.3) 레이저 어닐링 공정에 대한 문헌 조사 3
• 1.2. 연구 목적 3
• II. 실험 방법 5
• 2.1. 실험 장치 및 재료 5
• 2.2. 레이저 어닐 공정 조건 8
• 2.3. 분석 방법 9
• III. 모델링 방법 10
• 3.1. 계산 영역 설정 10
• 3.2. 지배 방정식과 경계 및 초기 조건 10
• 3.2. 물성치 12
• IV. 결과 및 분석 15
• 4.1. 실험 결과 15
• 4.1.1) 기초 실험 15
• 4.1.2) 어닐 시편 표면 및 단면 형상 분석 17
• 4.1.3) 어닐 시편 표면 거칠기 분석 19
• 4.1.4) 격자 구조 및 결정성 분석 23
• 4.2. 시뮬레이션 결과 27
• 4.2.1) 시간에 따른 표면 온도 변화 27
• 4.2.1) 용융 지속 시간 분석 29
• V. 결 론 30
• CONTRIBUTIONS 32
• REFERENCES 33
• ABSTRACT 38
• CURRICULUM VITAE 40