-
椭偏仪难以精确测量透明衬底上吸收薄膜光学常数的原因:1)衬底的背面反射光为非相干光, 它的存在会极大的增加拟合难度; 2)衬底光学常数(折射率和消光系数)的差异会影响测量的准确性, 而且会在吸收薄膜的光学常数中表现出来, 需要单独测量其光学常数; 3)厚度与光学常数之间呈现强烈的关联性. 针对以上三个问题, 选择石英玻璃、载玻片、盖玻片和普通浮法玻璃作为研究对象. 采用折射率匹配法消除上述衬底背面反射光的影响. 结果显示, 折射率匹配法能够有效消除折射率在1.43-1.64、波长范围为190-1700 nm波段的石英、浮法玻璃等透明衬底的背面反射光. 之后, 通过拟合椭偏参数ψ和垂直入射时的透过率T0 分别得到以上衬底的折射率和消光系数. 拟合得到的结果与文献报道的趋势一致. 最后, 采用椭偏参数和透过率同时拟合的方法(SE+T法)得到类金刚石薄膜(沉积在石英玻璃上)和非晶硅薄膜(沉积在载玻片、盖玻片上)光学常数和厚度的准确解.The determination of the optical constants of absorbing films, particularly on opaque substrates, is a difficult problem when solely using spectroscopic ellipsometry. First, unwanted backside reflections are incoherent with the desired reflection from the front side, which makes the fitting of optical constants difficult. Second, the optical constants of substrate must be carefully characterized in advance, as any small absorption in the substrate would be mixed into the film’s overall optical constants. Third, thickness and optical constants are strongly correlated with each other, which may prevent a unique solution for absorbing films. For the above reasons, quartz, glass slide, cover glass and float glass substrates are studied. Backside reflections of the substrates are suppressed by index matching technique. The results show that the simple technique works well for substrate materials with refractive index in a range from 1.43 to 1.64, including materials such as fused silica, float glass, etc. in a spectral range from 190 nm to 1700 nm. The refractive index and extinction coefficient of the substrate are fitted by ellipsometricψdata and the normal spectral transmittance T0. The results are consistent with the literature reported. Finally, a Combined ellipsometry and transmission approach is used to determine the thickness values and optical constants of the diamond-like carbon (DLC) film coated on the quartz and the amorphous silicon (a-Si) film coated on the glass slide and cover glass accurately.
[1] Swanepoel R 1983 J. Phys. E:Sci. Instrum. 16 1214
[2] Swanepoel R 1984 J. Phys. E:Sci. Instrum. 17 896
[3] Hilfiker J N, Singh N, Tiwald T, Convey D, Smith S M, Baker J H, Tompkins H G 2008 Thin Solid Films 516 7979
[4] McGahan W A, Johs B, Woollam J A 1993 Thin Solid Films 234 443
[5] Jellison Jr G E, Merkulov V I, Puretzky A A, Geohegan D B, Eres G, Lowndes D H, Caughman J B 2000 Thin Solid Films 377 68
[6] Jellison Jr G E, Modine F A 1996 Appl. Phys. Lett. 69 371
[7] He J, Li W, Xu R, Guo A R, Qi Q C, Jiang Y D 2008 Acta. Phys. Sin. 57 7114 (in Chinese) [何剑, 李伟, 徐睿, 郭安然, 祁康成, 蒋亚东 2008 57 7114]
[8] Ma J M, Liang Y, Gao X Y, Chen C, Zhao M K, Lu J X 2012 Acta. Phys. Sin. 61 056106 (in Chinese) [马姣民, 梁艳, 郜小勇, 陈超, 赵孟珂, 卢景霄 2012 61 056106]
[9] Franta D, Ohlídal I, Buršíková V, Zajíčková L 2004 Thin Solid Films 455 393
[10] Tompkins H G, Tasic S 2000 J. Vac. Sci. Technol. A 18 946
[11] Zhou Y, Wu G S, Dai W, Li H B, Wang A Y 2010 Acta Phys. Sin. 59 2356 (in Chinese) [周毅, 吴国松, 代伟, 李洪波, 汪爱英 2010 59 2356]
[12] Synowicki R A, Johs B D, Martin A C 2011 Thin Solid Films 519 2907
[13] Fujiwara H 2007 Spectroscopic ellipsometry:principles and applications (Chichester:John Wiley & Sons) p138
[14] Forcht K, Gombert A, Joerger R, Köhl M 1997 Thin Solid Films 302 43
[15] Hayton D J, Jenkins T E 2004 Meas. Sci. Technol. 15 N17
[16] Synowicki R A 2008 Phys. Status Solidi C 5 1085
[17] Kitamura R, Pilon L, Jonasz M 2007 Appl. Optics 46 8118
[18] Bruggeman D A G 1935 Ann. Phys.-Berlin 24 636
[19] Fujiwara H, Koh J, Rovira P I, Collins R W 2000 Phys. Rev. B 61 10832
[20] Colombin L, Jelli A, Riga J, Pireaux J J, Verbist J 1977 J. Non-Cryst. Solids 24 253
[21] Dugnoille B, Virlet O 1994 Appl. Optics 33 5853
[22] Zhao J M, Yang P 2012 Microsystem Technologies 18 1455
-
[1] Swanepoel R 1983 J. Phys. E:Sci. Instrum. 16 1214
[2] Swanepoel R 1984 J. Phys. E:Sci. Instrum. 17 896
[3] Hilfiker J N, Singh N, Tiwald T, Convey D, Smith S M, Baker J H, Tompkins H G 2008 Thin Solid Films 516 7979
[4] McGahan W A, Johs B, Woollam J A 1993 Thin Solid Films 234 443
[5] Jellison Jr G E, Merkulov V I, Puretzky A A, Geohegan D B, Eres G, Lowndes D H, Caughman J B 2000 Thin Solid Films 377 68
[6] Jellison Jr G E, Modine F A 1996 Appl. Phys. Lett. 69 371
[7] He J, Li W, Xu R, Guo A R, Qi Q C, Jiang Y D 2008 Acta. Phys. Sin. 57 7114 (in Chinese) [何剑, 李伟, 徐睿, 郭安然, 祁康成, 蒋亚东 2008 57 7114]
[8] Ma J M, Liang Y, Gao X Y, Chen C, Zhao M K, Lu J X 2012 Acta. Phys. Sin. 61 056106 (in Chinese) [马姣民, 梁艳, 郜小勇, 陈超, 赵孟珂, 卢景霄 2012 61 056106]
[9] Franta D, Ohlídal I, Buršíková V, Zajíčková L 2004 Thin Solid Films 455 393
[10] Tompkins H G, Tasic S 2000 J. Vac. Sci. Technol. A 18 946
[11] Zhou Y, Wu G S, Dai W, Li H B, Wang A Y 2010 Acta Phys. Sin. 59 2356 (in Chinese) [周毅, 吴国松, 代伟, 李洪波, 汪爱英 2010 59 2356]
[12] Synowicki R A, Johs B D, Martin A C 2011 Thin Solid Films 519 2907
[13] Fujiwara H 2007 Spectroscopic ellipsometry:principles and applications (Chichester:John Wiley & Sons) p138
[14] Forcht K, Gombert A, Joerger R, Köhl M 1997 Thin Solid Films 302 43
[15] Hayton D J, Jenkins T E 2004 Meas. Sci. Technol. 15 N17
[16] Synowicki R A 2008 Phys. Status Solidi C 5 1085
[17] Kitamura R, Pilon L, Jonasz M 2007 Appl. Optics 46 8118
[18] Bruggeman D A G 1935 Ann. Phys.-Berlin 24 636
[19] Fujiwara H, Koh J, Rovira P I, Collins R W 2000 Phys. Rev. B 61 10832
[20] Colombin L, Jelli A, Riga J, Pireaux J J, Verbist J 1977 J. Non-Cryst. Solids 24 253
[21] Dugnoille B, Virlet O 1994 Appl. Optics 33 5853
[22] Zhao J M, Yang P 2012 Microsystem Technologies 18 1455
计量
- 文章访问数: 6765
- PDF下载量: 337
- 被引次数: 0
下载:
