Measuring deflection to determine a characteristic of a cantilever

A method for determining a stress induced by a first process, the method comprising:

• directing collimated first light toward a first original target;
• determining an angle between the first directed light and a normal to the first original target;
• first receiving some of the first directed light as reflected from the first original target;
• determining a first position where the first reflected light is received;
• subjecting the first original target to the first process;
• directing collimated second light toward the first processed target;
• second receiving some of the second directed light as reflected from the first processed target;
• determining a second position where the second reflected light is received;
• based, at least in part, on the determined angle and on the first and second determined reception positions, calculating a deflection induced into the first processed target;
• and
• based, at least in part, on the calculated induced deflection, calculating a stress induced by the first process into the first processed target, and further comprising;
• repeating said steps with a second target and a second process, the second target distinct from the first target, and the second process distinct from the first process;
• comparing the calculated stress induced by the first process into the first processed target with the calculated stress induced by the second process into the second processed target;
• and
• based, at least in part, on the comparison of the calculated induced stresses, preparing a recommendation of one of the first and second processes.