A semianalytical solution for the 3ω method including the effect of heater thermal conduction

A semianalytical solution for the 3ω method is derived to account for thermal conduction within the metallic heater. The existing uniform heat flux approximation between the metal heater and substrate is replaced by a more realistic uniform heat generation condition within the metal heater. Although this correction does not affect thermal conductivity measurements in the original 3ω method, it is shown that significant errors can result when it is applied for thermal conductivity anisotropy measurements. For low thermal conductivity films, the error in the anisotropy ratio can be as high as 50%.