Plasma surface treatment of local modify silicon plates

This paper presents a study of the use of silicon Si for element base manufacture of micro- and nanoelectronics by using combined methods of focused ion beams and atomic layer plasma chemical etching. This technology makes it possible to modify surface of Si substrates in the required topology and geometry, followed by removal of atoms to obtain nanoscale elements. The influence of parameters of method of focused ion beams and plasma chemical etching on parameters of the formed structures is analyzed. So, for example, for formation of structures with maximum roughness, it is necessary to increase values of parameters responsible for reactive ion etching, these are such parameters as: the power of capacitive plasma source, the mixing voltage, and the flow rate of an inert gas (argon).

Study of nonlinear optical phenomena in silicon nanowires

This work studies generation of second and third harmonics in arrays of vertically oriented silicon nanowires (SiNWs) encapsulated into a silicone membrane and separated from the growth substrate. The structures were produced by plasma-chemical etching of silicon substrate resulting in a formation of homogeneous arrays of SiNWs. Such SiNW-based membranes demonstrated efficient infrared-to-visible light conversion by generation of second and third harmonic signals visible by a naked eye. This study contributes to the development of technology of optical devices based on silicon and presents a new route for visualization of infrared radiation.

Fabrication of Superconducting Nb–AlN–NbN Tunnel Junctions Using Electron-Beam Lithography

Mixers based on superconductor–insulator–superconductor (SIS) tunnel junctions are the best input devices at frequencies from 0.1 to 1.2 THz. This is explained by both the extremely high nonlinearity of such elements and their extremely low intrinsic noise. Submicron tunnel junctions are necessary to realize the ultimate parameters of SIS receivers, which are used as standard devices on both ground and space radio telescopes around the world. The technology for manufacturing submicron Nb–AlN–NbN tunnel junctions using electron-beam lithography was developed and optimized. This article presents the results on the selection of the exposure dose, development time, and plasma chemical etching parameters to obtain high-quality junctions (the ratio of the resistances below and above the gap Rj/Rn). The use of a negative-resist ma-N 2400 with lower sensitivity and better contrast in comparison with a negative-resist UVN 2300-0.5 improved the reproducibility of the structure fabrication process. Submicron (area from 2.0 to 0.2 µm2) Nb–AlN–NbN tunnel junctions with high current densities and quality parameters Rj/Rn > 15 were fabricated. The spread of parameters of submicron tunnel structures across the substrate and the reproducibility of the cycle-to-cycle process of tunnel structure fabrication were measured.

Application of plasma chemical treatment for manufacturing of instrument microstructures based on gallium nitride

The epitaxial layers of n-n+-GaN were processed by plasma-chemical etching using a Sentech SI 500 unit equipped with an inductively coupled plasma source. The regimes of gallium nitride processing in chlorine plasma have been established, which make it possible to remove epitaxial layers of the semiconductor down to a depth of 10 μm with a smooth surface. Based on the obtained processing results, prototype samples of Schottky diode microstructures with quasi-vertical contact geometry were manufactured. The effect of pretreatment on the characteristics of instrument microstructures is demonstrated.

Effect of the Etching Profile of a Si Substrate on the Capacitive Characteristics of Three-Dimensional Solid-State Lithium-Ion Batteries

Along with the soaring demands for all-solid-state thin-film lithium-ion batteries, the problem of their energy density rise becomes very acute. The solution to this problem can be found in development of 3D batteries. The present work deals with the development of a technology for a 3D solid-state lithium-ion battery (3D SSLIB) manufacturing by plasma-chemical etching and magnetron sputtering technique. The results on testing of experimental samples of 3D SSLIB are presented. It was found that submicron-scale steps appearing on the surface of a 3D structure formed on Si substrate by the Bosch process radically change the crystal structure of the upper functional layers. Such changes can lead to disruption of the layers’ continuity, especially that of the down conductors. It is shown that surface polishing by liquid etching of the SiO2 layer and silicon reoxidation leads to surface smoothing, the replacement of the dendrite structure of functional layers by a block structure, and a significant improvement in the capacitive characteristics of the battery.

FEATURES OF PLASMA CHEMICAL ETCHING OF LITHIUM TANTALATE SUBSTRATE (LiTaO3)

The results of researches of plasma chemical treatment of lithium monocrystalline tantalate (LiTaO3) from gas type, bias voltage (energy of chemically active ions) and from current of additional bias generator are given. A closed-loop electron drift plasma chemical reactor and gas mixtures containing Ar, Ar + ClС4, and Ar + SF6 were used for the experiments. It was found that the etching rate of LiTaO3 for the discharge in the gas mixture Ar + CCl4 is 14 times higher than all other mixtures that were used. It is shown that the proposed idea and approaches of LiTaO3 processing can be effectively applied for the production of optical systems with a minimum core thickness of about 2…3 μm.

FREQUENCY TRIMMING OF THE STW RESONATORS WITH WORKING FREQUENCY UP TO 1 GHZ

This paper presents the data for frequency trimming of the single port STW resona-tors in a frequency range of 500–1000 MHz by plasma chemical etching method. The main parameters of resonators after frequency trimming are given: frequency tolerance <±100·10–6, quality factor of 8600–9500, equivalent elements needed for use of the STW resonators.

Изготовление сверхпроводниковых туннельных структур с использованием электронно-лучевой литографии

The technology for manufacturing submicron Nb - AlN - NbN tunnel junctions using electron beam lithography has been developed and optimized. Investigations have been carried out to select the exposure dose, development time, and plasma-chemical etching parameters to obtain the high quality of junctions (the ratio of the resistances below and above the gap Rj/Rn). The use of a negative resist ma-N 2400 with lower sensitivity and better contrast in comparison with a negative resist UVN 2300-0.5 has improved the reproducibility of the structure fabrication process. The submicron (area from 2.0 to 0.2 µm2) tunnel junctions Nb - AlN - NbN with high current density and quality parameter Rj / Rn> 15 were fabricated. The spread of parameters of submicron tunnel structures across the substrate and the reproducibility of the cycle-to-cycle process of fabrication of tunnel structures has been experimentally measured.

Плазмохимическое и жидкостное травление в постростовой технологии каскадных солнечных элементов на основе гетероструктуры GaInP/GaInAs/Ge

Investigation and development of a separating mesa-structure creating technology for fabricating multi-junction solar cells based on the GaInP/GaInAs/Ge heterostructure has been carried out. Studied were methods of etching of heterostructure layers: liquid chemical etching in the etchants based on HBr, H2O2, K2Cr2O7 and plasma-chemical etching in the stream of operating gas BCl3. The comparative analysis of etching methods was studied. The protective masks based on photoresist layer and TiOx/SiO2 were developed. Multi-junction solar cells with low parameters of leakage current less than 10-7 A at voltage 0,5-1 V were created.

Исследование методов текстурирования светодиодов на основе гетероструктур AlGaAs/GaAs

Investigations of methods for texturing the light-emitting surface of IR light-emitting diodes (LEDs) (wavelength 850 nm) based on AlGaAs/GaAs heterostructures with Bragg reflectors have been carried out. Developed were methods of liquid and plasma-chemical etching of solid solution for creating peaks (pyramids) of different form, 0.2–1.5 µm height. Estimation of the effect of texturing methods and also configuration of peaks on the light-emitting diode electroluminescence intensity has been performed. The increase of the electroluminescence intensity by 25% has been achieved.