Shoya Yamakawa1,2,Hiromitsu Kato2,Masahiko Ogura2,Yukako Kato2,Toshiharu Makino2,Ryota Tsukamoto1,2,Daisuke Takeuchi2,1,Ichiro Shoji1
Chuo University1,National Institute of Advanced Industrial Science and Technology (AIST)2
Shoya Yamakawa1,2,Hiromitsu Kato2,Masahiko Ogura2,Yukako Kato2,Toshiharu Makino2,Ryota Tsukamoto1,2,Daisuke Takeuchi2,1,Ichiro Shoji1
Chuo University1,National Institute of Advanced Industrial Science and Technology (AIST)2
Diamond is well-known as an ultimate material because of its superior properties and it is expected to be employed in next-generation power electronic devices. One of the unique properties of diamond is the electron emission from negative electron affinity (NEA) surfaces. A vacuum power switch using a vertical-type PIN diamond diode was reported, which was made use of electron emission from NEA surfaces obtained by hydrogen-termination, and switching at 10kV was demonstrated. [1] The vertical PIN diodes were fabricated on a p-type substrate and the mesa diodes were fabricated by ICP etching, since there is no n-type conductive substrate. Then in this study, we attempted to fabricate planer-type diodes on Ib(111) substrates using selective growth technique, which could avoid damage in the device caused by ICP etching. As a result, the planer-type PIN diodes fabricated successfully showed electron emission by turning on, and the highest electron emission efficiency was close to 1%, which was comparable to the vertical-type one. It means that the planer-type diodes have a potential of high electron emission efficiency as well as the vertical-type ones, even the body was fabricated only by thin-films. Since it is a planer-type, it is possible to apply not only for electron emitters, but also for quantum devices owing to its ease of observation from the top. In this paper, we will introduce such a high potential of the new planar diode-type electron emitters, with the discussion of electron emission mechanism.<br/><Acknowledgement><br/>We are grateful for huge collaborations in experiments and discussion from our AIST colleagues and technical staffs. This work was partially supported by MEXT-Program for Creation of Innovative Core Technology for Power Electronics Grant Number JPJ009777, The FUTABA Foundation, and MEXT Quantum Leap Flagship Program (MEXT Q-LEAP) Grant Number JPMXS0118067395. Part of this work was also performed under the Cooperative Research Program of "Network Joint Research Center for Materials and Devices," which was carried out with Dr. Abukawa in Tohoku University.<br/><br/>[1]: D. Takeuchi, S. Koizumi, T. Makino, H. Kato, M. Ogura, H. Ohashi, H. Okushi , S. Yamasaki,“Negative electron affinity of diamond and its application to high voltage vacuum power switches,” Phys. Status Solidi, 2013.