I would recommend that you try treating the surface of the substrates with UV-ozone which usually improves the surface energy and coatibility of the substrates. 10 minutes should be enough.

Are you sure about cleanness of your substrate? Any contamination on the substrate surface can cause interfere in film adhering. Also pretreatment of substrate as @Gunel Huseynova said, may be helping.

Also let the substrate to be cold in the furnace medium, after the treatment.

Yes I am sure about cleanliness of substrate but still I will take care about the said.Thank you for your valuable suggestions.

Dear Sachin Padwal

Are you using absolute ethanol or ethanol 96%?

Best regards

Sir I am using ethanol AR 99.9%

Yes dear, you should change to ethanol 96% .The 4% water in ethanol is necessary for titanium isopropoxide hydrolysis completion:

Hydrolysis reaction

Ti(OR)4 + 4H2O → Ti(OH)4 + 4ROH

where R is i-propyl

Best regards

Thank u dear sir@mohammed huussein.

Dear Sachin Padwal,

can you test a way to slow down, before the annealing, thermal pre-treatment processing ?

In other words, can you

1) increase the oven's Temperature very slowly, and/or can you

2) cover your sample, in order to protect it from a (possible) Temperature overshooting ?

I will do the things as per your suggestion dear sir@Ioannis Samaras.

I am attaching one good article from Beijing University for your kind reference. Hope it help.

Oh very thank u @Bukhari sir