CVD Process
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Nitride 방식 : LPCVD (Low Pressure Chemicla Vapor Deposition) for low stress
Wafer Size : 4", 5", 6", 8" (Min. 25ea)
Thickness : 주 1,000Å-3,000Å
Delivery : 1~2주이내
Uniformity : 1%~3% 이내
CVD 공정과 장비
일반적 Silicon Nitride by LPCVD 과 PECVD 막의 Property 비교표
Property HT_CVD-NP 900℃ PE_CVD-LP 300℃
Composition Si3N4 SixNyHz
Si / N ratio 0.75 0.8 - 1.0
Density 2.8-3.1g/cm3 2.5-2.8g/cm3
Refractive Index 2.0 - 2.1 2.0 - 2.1
Dielectric constant 6 - 7 6 - 9
Dielectric strength 1 x 10E7 V/cm 6 x 10E6 V/cm
Bulk resistivity 10E15 - 10E17 ohms/square 10E15 ohms/square
Surface resistivity >10E13 ohms/square 1 x 10E13 ohms/square
Stress at 23℃ on Si 1.2 - 1.8x10E10 dyne/cm2
(tensile)		 1 - 8x10E9 dyne/cm2
( Compressive)
Thermal expansion 4x10E-6 /℃ >4<7x10E-6/℃
Color,transmitted None Yellow
Step coverage Fair Conformal
H2O permeability Zero Low-none
Thermal stability Excellent Variable>400℃
Solutionetch rate
HFB (20-25℃) 10 -15Å/min 200 - 300Å/min
49% HF (23℃) 80Å/min 1,500 - 3,000Å/min
85% H3PO4 (155℃) 15Å/min 100 - 200Å/min
85%H3PO4 (180℃) 120Å/min 600 - 1,000Å/min
Plasmaetch rate
70% CF4 / 30%O2, 150w,100℃ 200Å/min 500Å/min
Na+ penetration <100Å <100Å
Na+ retained in top 100Å >99% >99%
IR absorption
Si-N max ~ 870 cm-1 ~ 830 cm-1
Si-H minor - 2180 cm-1

일반적으로, LP CVD silicon nitride는 대개 700-800℃사이의 온도에서 dichlorosilane (SiCl2H2)와 ammonia(NH3)의 반응에의해 형성됩니다. 반응식은 다음과 같습니다.

3SiCl2h2 (gas) + 4NH3 (gas) => Si3N4 (solid) + 6HCl (gas) + 6H2 (gas)