I presume you are talking about "active clamping", e.g. made with a high voltage z-diode feed back to an internal gate driver node before the output buffer.
It's purpose is clamping of Vce overvoltage and avoid IGBT damage, e.g. when switching off an inductive load. It should be never required in a correctly layouted half bridge where overvoltages are clamped to Vbus by design.