How difficult is it to become an Engineer with an Undergraduate Degree in Physics?

I am torn between studying physics and studying engineering. Could I realistically move into engineering if I study physics as an undergrad?

Not without transferring if the initial undergrad school u select doesn’t have an engineering major.

Yes, you can find a job in engineering with a physics degree if you judiciously choose your elective courses to include a significant amount of design or if you choose an Engineering or Applied Physics degree, where that kind of course material is built into the curriculum.

I work in 300mm semiconductor fab and deal with engineers with Physics background (mostly PhD).

I know a few engineers who work as engineers with physics degrees, although some (not all!) went on to get engineering graduate degrees.