Hi Johneph,

please tell us a litte bit more about your film; e.g. material composition, kind of film production, thickness and procedure of smoothing.....substrate etc.

Now we could only guess and perform a brain storming

The thickness is sub 10 nm , and smooth thin film because when I checked the roughness through AFM ,it is around 0.40 nm

And what is your material (and kind of production) and substrate. Only rough description (because it may be a secret).

 The thickness isn't that much (less than about 50 atomic distances). What is the value of diameter of your pinholes.

It may be that the beginning of the film growth is characterized by isle growing. The formation to a complete continuous material layer has not yet took place up to the 50th atomic layer. Please see  for example the link at the chapter 'growth mode' (Volmer-Weber mode).

I think you should perhaps use an intermediate layer for better adhesion or modify the film processing parameters.

But without more detailed informations all these thoughts are pure speculations.

The roughness of your film is extraordinary (about 2 atomic layers); perfect! 

Congratulations.

https://en.wikipedia.org/wiki/Thin_film

I observed the pinhole in lesser thickness films and it will solved after depositing further more thickness on same slide.

It also depends on the deposition method you preferred and the rate of deposition.

Double step deposition might do the trick it seems 

Pin hole formation could be due to different reasons. Here are some of them.

- Thin film being deposited

     You have < 10 nm film

- Unclean substrates or unclean environment used for deposition. They could be a dust particle which can stick to the substrates and later on it can disappear leading to the formation of a pin hole.

- If the deposited material is not compatible with your substrate either it is not sticking or there is no lattice matching then that could lead to island formation and can lead to pin hole formation.

- Substrate temperature during deposition. Higher temperatures can lead to annealing and if the film is thin then that can lead to island formation.

Can double deposition help in reducing the pin holes ?

It can help in certain cases.

To give a more relevant answer, I will need answers to some of these questions.

1. What are you depositing organic material or inorganic material?

2. What is the substrate temperature?

3. How are you depositing the film?

It is a metal gold .20 C substrate temp and sputtering

What is the substrate?

Si

Double deposition may help in some cases depending on the application you are looking for but it is generally not recommended.