Is there any possibility of dissecting a microchip to get data from its internal memory?
In general yes that is possible. For example a guy called Christopher Tarnovsky managed to tap the inner data paths of a Trusted Platform Module. He used acid to remove the encapsulation, rust remover to get rid of some mesh and then managed to probe the circuit and intercept internal communications.

Obviously on such a small scale it is a non-trivial excercise, but there is no theoretical reason I'm aware of why you couldn't disconnect the address and data bus of an on-chip ROM for example and read back the contents once you have physical access to it.