초록 |
Van der Waals (vdW) materials and their heterostructures, weakly combined by vdW force, have attracted extensive interests due to their unique properties and a large degree of freedom in designing new materials systems and advanced electronic devices. We found that graphene can be used as etch masks and etch stops in XeF2 etching process of vdW heterostructures. By using graphene etch masks, low resistance via-contacts can be fabricated for the embedded graphene in hexagonal boron nitride (hBN), leading to extremely small contact resistance and ultrahigh mobility. By using this fabrication technique, we also developed vertically integrated inverters consisting of entirely 2D materials. |