System and method for selectivity etching an integrated circuit

A method for selectively exposing a region of integrated circuit (IC) die, the method comprising:

• providing an IC die with a first region, located on a backside surface of a bulk silicon (Si) layer;
• forming a semi-transparent film overlying the bulk Si layer, semi-transparent to light having a first wavelength;
• irradiating the semi-transparent film with light having the first wavelength;
• in response to irradiating the semi-transparent film with a first power density, locating the IC die first region;
• in response to irradiating the semi-transparent film with a second power density, greater than the first power density, marking a region of the semi-transparent film;
• selectively etching a region of the bulk Si layer underlying the semi-transparent film marked region;
• and,
• exposing the IC die first region.

A method for selectively marking a region of integrated circuit (IC), the method comprising:

• providing an IC die with a first region located on a backside surface of a bulk silicon (Si) layer;
• forming a semi-transparent film overlying the bulk Si layer, semi-transparent to light having a first wavelength;
• irradiating the semi-transparent film with light having the first wavelength;
• in response to irradiating the semi-transparent film with a first power density, locating the IC die first region;
• in response to irradiating the semi-transparent film with a second power density, greater than the first power density, marking a region of the semi-transparent film;
• selectively etching a region of the bulk Si layer underlying the semi-transparent film marked region;
• irradiating the selectively etched region of the bulk Si layer with a focused ion beam (FIB);
• and,
• in response to the FIB, exposing the IC die first region.