Kemal is right. Go to the grazing incidence regime and perform a scan around the critical angle of total reflection. From the period of the upcomming Kiessig interference fringes you can estimate the film thickness. Please search in Google for 'Kiessig fringes'.

XRD pattern also shows some small satellite peaks (a kind of extra peaks) near the main peak in case of thin film. if those peaks can be identified properly then only u can estimate its film thickness but this method is full of errors.

Thanks a lot Sachin Kumar

You can use grazing incidence XRD (GIXRD); meaning the X-Rays are sent almost parallel to the surface (typically lower than α

Kemal is right. Go to the grazing incidence regime and perform a scan around the critical angle of total reflection. From the period of the upcomming Kiessig interference fringes you can estimate the film thickness. Please search in Google for 'Kiessig fringes'.

Yes it can, the best method is X-Ray Reflectivity if u had the optics (parallel beam, knife edge, 0D detector)

Gracing Incidence or Gracing Exit XRD, vary the angle (omega) as scan the highest peak of the subtrate until it disapear. The angle than use to calculate the penetration depth to ur film. But this is quite rough method as the density of the film depend on the film quality. The setup is parallel beam and equatorial soller or Parallel Plate Collimator, but for very thin film u need X-Ray lens or Polycap with in-plane setup.

You can use grazing incidence radiation diffraction to depth profile of phase abundance behavior especially at the near surface. First find the critical angle (αc) by using: αc = 1.6 x 10-3 ρ λ, with ρ = density of your sample and λ = the wavelength of X-ray. (Barner, 1992: Dynamic Diffraction studies on the synthesis of ceramics using synchrotron radiation, trans. J. Br. Ceram. Soc., 91(1), 26-29). Then you can find penetration depth, l,  by using formula ( (Vineyard, 1982: Grazing-incidence Diffraction and the distorted-wave approximation for the study of surface, Physiscal Review B 26(8) 4146-4158). For more information you can download my thesis from Curtin University, Perth, 2001 (page 160-162). I thought you can download it for free.

XRR - X-ray Reflectivity!

1. What materials? Substrate/Film?

2. What method was used for creating the thin film?

3. What is the expected film thickness?

https://www.researchgate.net/post/What_depths_can_one_typically_probe_with_XRR_X-ray_Reflectivity_Reflectometery

Hello, why are you going to use XRD to measure the thickness of thin film? Better you can think about Non-contact mode profilometer (laser based) or ellipsometer. These are rather convenient!!!