DateTime Serialization UTC C# Driver

yyyy-MM-ddTHH:MM:SS.000000Z

I have a date with UTC in C#; currently, when I store in Mongo Database it holds only as yyyy-MM-ddTHH:MM:SS.SSSZ but I want to increase precision to yyyy-MM-ddTHH:MM:SS.ffffffZ.

So how can I do that?

Thanks
Marmik