A method and structure are provided for implementing vertical airgap structures between chip metal layers. Three non-rigid sidewalls are attached the rigid back wall and to one another to form a rectangular box. In a preferred embodiment, the tool is provided with a beveled lower edge to facilitate using the tool to slice bait. 75:1 to 8:1, even more preferably from 1:1 to 4:1, yet more preferably 1.