KASSAMAKOV, Ivan,MONTONEN, Risto,HÆGGSTRÖM, Edward,Kontiola, Antti,Salmi, Ari
申请号：
FI20165576
公开号：
FI20165576A
申请日:
2016.07.11
申请国别(地区):
FI
年份:
2018
代理人:
摘要：
A device for measuring an optical thickness of a layer (110)consisting of one or more materials comprises a measurement section (103) for producing measurement results based on interference between optical waves reflected from the layer and optical waves reflected from a reference reflector (102). The device comprises a modifier section (104) for changing the optical length of a reference optical path comprising the reference reflector and/or the optical length of a measurement optical path comprising the layer. The optical thickness is estimated based on: a first measurement result indicative of a position of a first surface of the layer and measured with a first value of the optical length, a second measurement result indicative of a position of the second surface of the layer and measured with a second value of the optical length, and a difference between the first and second values of the optical length.
