Semi-invasive IC program crack are not entirely new. UV light has been used to disable security fuses in EPROM and OTP microcontrollers for many years.
Modern microcontrollers are less susceptible to this MCU cracking as they were designed to withstand it. More information on the evolution of defences against UV breaking in microcontrollers later. Advanced imaging techniques can be considered as semi-invasive as well.
This includes various kinds of microscopy such as infrared, laser scanning and thermoimaging. Some of them can be applied from the rear side of the chip which is very useful for modern chips with multiple metal layer design. Some of these techniques allow observation of the state of each individual transistor inside the chip.