TTA 4:2002 proposes a standard procedure for the three-omega method for measuring the thermal conductivity of a thin, electrically insulating film, on a substrate having a thermal conductivity significantly greater than the thermal conductivity of the film.This method is applicable to a film on a silicon substrate with the following characteristics:
a) the film is electrically insulating;
b) the film has a thermal conductivity that is less than one tenth the thermal conductivity of silicon;
c) the film is uniform in thickness and the thickness lies in the range 0,25 to 1 micrometres.
d) the maximum dimensions of the film are limited by the sizes of the preparation and measurement apparatus;
e) the minimum dimensions of the film are limited by the minimum size of the circuit element that can be placed on the film surface.
NOTE A specimen approximately 15 mm by 25 mm is of an appropriate size although specimens as small as 10 mm by 10 mm are usable.
The method is directly applicable to films of silicon dioxide on silicon wafer substrates.
The method may be applicable to insulating films on other high-thermal conductivity substrates provided that the parameters of the substrate material are substituted for the parameters of silicon used in this method and the associated computer program.
The method is applicable to measurements near room temperature.