Atomic and Close-to-Atomic Scale Manufacturing:A Review on Atomic Layer Removal Methods Using Atomic Force Microscopy

Manufacturing at the atomic scale is the next generation of the industrial revolution.Atomic and close-to-atomic scalemanufacturing(ACSM)helps to achieve this.Atomic force microscopy(AFM)is a promising method for this purposesince an instrument to machine at this small scale has not yet been developed.As the need for increasing the number ofelectronic components inside an integrated circuit chip is emerging in the present-day scenario,methods should be adoptedto reduce the size of connections inside the chip.This can be achieved using molecules.However,connecting moleculeswith the electrodes and then to the external world is challenging.Foundations must be laid to make this possible for thefuture.Atomic layer removal,down to one atom,can be employed for this purpose.Presently,theoretical works are beingperformed extensively to study the interactions happening at the molecule-electrode junction,and how electronic transportis affected by the functionality and robustness of the system.These theoretical studies can be verified experimentally only if nano electrodes are fabricated.Silicon is widely used in the semiconductor industry to fabricate electronic components.Likewise,carbon-based materials such as highly oriented pyrolytic graphite,gold,and silicon carbide find applications inthe electronic device manufacturing sector.Hence,ACSM of these materials should be developed intensively.This paperpresents a review on the state-of-the-art research performed on material removal at the atomic scale by electrochemical andmechanical methods of the mentioned materials using AFM and provides a roadmap to achieve effective mass productionof these devices.

Ultrahigh-performance planar β-Ga2O3 solar-blind Schottky photodiode detectors

The low dark current, high responsivity and high specific detectivity could be preferably achieved in detectors based on junctions, owing to the efficient constraint of carriers. Compared with the other junctions, planar Schottky junctions have simple structures and technological demands and are easy integrated. Herein, in this work, we prepared the β-Ga_(2)O_(3) thin film by metalorganic chemical vapor deposition method to construct planar Ti/β-Ga2O3/Ni Schottky photodiode detectors with different onstate resistances. Fortunately, all the devices exhibit state-of-the-art performances, such as responsivity of 175–1372 A W^(-1),specific detectivity of 10^(14) Jones and external quantum efficiency of 85700%–671500%. In addition, the dependences of device performances on the on-state resistances indicate that the higher dark currents, photocurrents and photoresponsivities may well be obtained when on-state resistance is smaller, due to the less external power is used to overcome the impendence and condensance at the Ti/β-Ga_(2)O_(3) and Ni/β-Ga_(2)O_(3) interfaces, but contributing to higher electric current flow both in the dark and under illuminations.