What is the HSM 2's chip?

I am looking for a solution to store my Root Keys.

Does the HSM 2 use STM32 to store keys? If so, I may need a higher standard tool to store root keys.

I am curious: what would be a higher standard for you ?

Also you are aware the uController makes the communication, but the keys would be stored on a secure card. So in case somebody get’s physical the key, could always bridge the built-in uController, nor ?

The chip is a NXP JCOP3 (J3H145) based on the P60 secure micro controller.

For Nitrokey HSM 2, STM32 is used on the device for the USB communication only, between the host and the smart card. The latter is based on a chip as described in previous comment - What is the HSM 2's chip?.