The authors use scanning probe microscopy to reveal the atomic structures and nanoscale morphology of graphene-based electronic devices, specifically graphene sheets supported by an insulating silicon dioxide (SiO₂) substrate. They employ a novel cleaning process to produce atomically clean graphene sheets, which are then imaged using atomic-resolution scanning tunneling microscopy (STM). The results show that the graphene lattice is strongly perturbed, breaking the hexagonal symmetry and partially conforming to the underlying SiO₂ substrate. These perturbations are obscured or modified by photoresist residue, which is common in normal lithographic methods. The authors demonstrate that the resist residue can be effectively removed in an argon/hydrogen atmosphere at 400°C, revealing the intrinsic structural properties of the graphene sheet. The cleaned graphene sheets exhibit both triangular and hexagonal lattice patterns, indicating significant electron wave scattering. The thickness of the graphene film is measured to be 4.2 Å in ultra-high vacuum (UHV), confirming it as a monolayer. The 3-D morphology of the graphene sheet is also characterized, showing that it is approximately 60% smoother than the SiO₂ substrate. The observed corrugations in graphene on SiO₂ are attributed to the partial conformation of the graphene to the SiO₂ substrate rather than intrinsic corrugations. The study highlights the importance of considering resist residues in interpreting transport and structural measurements of graphene devices.The authors use scanning probe microscopy to reveal the atomic structures and nanoscale morphology of graphene-based electronic devices, specifically graphene sheets supported by an insulating silicon dioxide (SiO₂) substrate. They employ a novel cleaning process to produce atomically clean graphene sheets, which are then imaged using atomic-resolution scanning tunneling microscopy (STM). The results show that the graphene lattice is strongly perturbed, breaking the hexagonal symmetry and partially conforming to the underlying SiO₂ substrate. These perturbations are obscured or modified by photoresist residue, which is common in normal lithographic methods. The authors demonstrate that the resist residue can be effectively removed in an argon/hydrogen atmosphere at 400°C, revealing the intrinsic structural properties of the graphene sheet. The cleaned graphene sheets exhibit both triangular and hexagonal lattice patterns, indicating significant electron wave scattering. The thickness of the graphene film is measured to be 4.2 Å in ultra-high vacuum (UHV), confirming it as a monolayer. The 3-D morphology of the graphene sheet is also characterized, showing that it is approximately 60% smoother than the SiO₂ substrate. The observed corrugations in graphene on SiO₂ are attributed to the partial conformation of the graphene to the SiO₂ substrate rather than intrinsic corrugations. The study highlights the importance of considering resist residues in interpreting transport and structural measurements of graphene devices.