Index of content:
Volume 34, Issue 2, March 2016
- Papers from the 13th International Symposium on Sputtering and Plasma Processes
Role of low-energy ion irradiation in the formation of an aluminum germanate layer on a germanium substrate by radical-enhanced atomic layer deposition34(2016); http://dx.doi.org/10.1116/1.4932039View Description Hide Description
Radical-enhanced atomic layer deposition uses oxygen radicals generated by a remote microwave-induced plasma as an oxidant to change the surface reactions of the alternately supplied trimethylaluminum precursor and oxygen radicals on a Ge substrate, which leads to the spontaneous formation of an aluminum germanate layer. In this paper, the effects that low-energy ions, supplied from a remote microwave plasma to the substrate along with the oxygen radicals, have on the surface reactions were studied. From a comparative study of aluminum oxide deposition under controlled ion flux irradiation on the deposition surface, it was found that the ions enhance the formation of the aluminum germanate layer. The plasma potential measured at the substrate position by the Langmuir probe method was 5.4 V. Assuming that the kinetic energy of ions arriving at the substrate surface is comparable to that gained by this plasma potential, such ions have sufficient energy to induce exchange reactions of surface-adsorbed Al atoms with the underlying Ge atoms without causing significant damage to the substrate. This ion-induced exchange reaction between Al and Ge atoms is inferred to be the background kinetics of the aluminum germanate formation by radical-enhanced atomic layer deposition.
34(2016); http://dx.doi.org/10.1116/1.4933077View Description Hide Description
A Ni (200 nm)/CuxO (7 nm)/SiO2 (20 nm)/W structure is fabricated in order to investigate its resistive memory properties. The resistance of the Ni/CuxO/SiO2/W structure can be reversibly switched between a high-resistance state and a low-resistance state (LRS) by applied voltages in different polarities. According to the switching behavior, the results of cyclic voltammetry, and the positive temperature coefficient of the LRS resistance, the switching mechanism is dominated by the electrochemical reaction with Cu conducting filaments. This Ni/CuxO/SiO2/W structure lacks an active electrode, but still has the characteristics of an electrochemical resistive memory. The Cu xO layer provides Cu ions to form Cu conducting filaments during resistive switching. The Ni/CuxO/SiO2/W structure can also be operated in a vaporless environment, which overcomes the ambient issue for the traditional Cu/SiO2/W structure. The Ni/CuxO/SiO2/W structure exhibits reliable resistive switching and a lower ambient effect, and can be more flexibly integrated with complementary metal–oxide–semiconductor processes than the traditional Cu/SiO2/W structure.