[7a-S22-1~11] 13.8 Compound and power electron devices and process technology

[7a-S22-1] Nondestructive measurement of a homo-epitaxial grown GaN film thickness using FT-IR

〇FUMIMASA HORIKIRI¹, YOSHINOBU NARITA¹, TAKEHIRO YOSHIDA¹ (1.Sciocs Co. Ltd.)

Keywords:GaN, film thickness measurement, nondestructive

In this study, we demonstrate the nondestructive film thickness measurement of a homo-epitaxial layer grown on GaN substrate using FT-IR. Although the absorption coefficients for thin GaN layer on sapphire does not change significantly with the change in carrier concentration. In the low-dislocation GaN substrate, clear difference in optical constant was found to exist within near infrared range between the slightly-doped homo-epitaxial layer and the highly-doped substrate. Based on this finding, we have measured film thickness of GaN-on-GaN homo-epitaxial layer nondestructively using FT-IR. The estimated film thicknesses from FT-IR were agreed well with the results of secondary ion mass spectrometry (SIMS) analysis.