For Fig. 10.26, assume that a shield is placed vertically on the top layer of the chip, the shield width is 150 nm, the shield thickness is 200 nm, the shield spacing is 1 µm, a target probing point...

For Fig. 10.26, assume that a shield is placed vertically on the top layer of the chip, the shield width is 150 nm, the shield thickness is 200 nm, the shield spacing is 1 µm, a target probing point is located on M2 (in the quarter of two shield wires), the depth from shield layer to target point is 5 µm, a complete cut of shield wires can be detected, and a partial cut of shield wires is allowed. Answer the following questions:

(a) If only perpendicular milling is allowed (β = 90◦), can a FIB with 5 aspect ratio probe the target point without a complete cut of any shield wire?

(b) If angled milling is allowed (β ≤ 90◦), can a FIB with 5 aspect ratio probe the target point without a complete cut of any shield wire?