Antireflection coating on Si

e = λ r e f 4 n

Optimal thickness (nm)

Thickness Difference (TD)

Average Reflectance (%)

SiO2

103

106

3

14.3

ZrO2

69

72

3

9.4

TiO2

58

58

0

15

Al2O3

85

88

3

9.2

SiNx (n = 1.8)

81

85

4

9.1

SiNx (n = 2.2)

68

72

4

10.8

SiO2/TiO2

103/58

103/58

0/0

2.3

SiO2/ZrO2

103/69

103/69

0/0

3.6

SiO2/Al2O3

103/85

95/78

−8/−7

9.0

SiO2/SiNx (n = 1.8)

103/81

110/89

7/8

2.0

SiO2/SiNx (n = 2)

103/74

105/77

2/3

2.0

SiO2/SiNx (n = 2.2)

103/68

100/66

−3/−2

2.2