Shield Plate Bottom-Edge Geometry for Low-Heat Sample Ion Milling

The shield plate is designed with non-uniform thickness, where the thickness varies in the thickness direction. Specifically, certain regions have greater thickness to absorb more heat and prevent heat flow into the sample, while other regions have lesser thickness. This local variation in thickness creates different thermal mass distribution, allowing selective heat absorption at critical locations without compromising the overall shielding function or cross-section formation quality.

The invention changes the physical parameter of the shield plate by making the thickness non-uniform. Instead of a constant thickness, the shield plate has varying thickness values at different locations (greater thickness in some regions, lesser thickness in others). This parameter change optimizes the thermal properties of the shield plate, enabling it to absorb and dissipate heat more effectively while maintaining its protective function.

The shield plate employs local quality variation through non-uniform thickness distribution. Regions requiring enhanced heat absorption have greater thickness, while regions where minimal heat generation is acceptable have lesser thickness. This localized differentiation allows the shield plate to provide effective shielding coverage without uniformly generating excessive heat across the entire shielded area.

The invention converts the harmful effect of ion beam irradiation (heat generation) into a beneficial effect by strategically positioning greater thickness regions in the shield plate. These thicker regions act as heat sinks that absorb and dissipate the heat generated by ion beam interaction, preventing heat flow into the sample. Thus, the heat that would otherwise be harmful is redirected and managed through the optimized thickness distribution.