Dielectric filters made of PS: Advanced performance by oxidation and new layer structures

被引:133
作者
Berger, MG [1 ]
ArensFischer, R [1 ]
Thonissen, M [1 ]
Kruger, M [1 ]
Billat, S [1 ]
Luth, H [1 ]
Hilbrich, S [1 ]
Theiss, W [1 ]
Grosse, P [1 ]
机构
[1] RHEIN WESTFAL TH AACHEN, INST PHYS, D-52056 AACHEN, GERMANY
关键词
thermal oxidation; PS layers; oxidation;
D O I
10.1016/S0040-6090(96)09361-3
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
For the formation of PS dielectric filters a detailed calibration of the etch rates and refractive indices is required. The effective dielectric function of PS was determined for different substrate doping levels as a function of the anodization current density by fitting reflectance spectra. Based on these results a number of different dielectric filters were realized. For device applications a thermal oxidation step is necessary to reduce aging effects which occur as a result of the native oxidation of PS. In addition, thermal oxidation results in a qualitatively improve filter performance due to a reduced absorption in the PS layers. Therefore the dielectric functions of PS oxidized in dry O-2 at temperatures up to 950 degrees C were determined. A continuous variation of the porosity and hence the refractive index with depth was used to realize so-called rugate filters. This type of interference filter allows the design of structures with more complex reflectance or transmittance characteristics than structures consisting of discrete single layers. (C) 1997 Elsevier Science S.A.
引用
收藏
页码:237 / 240
页数:4
相关论文
共 19 条