7results about How to "Avoid etching" patented technology

This invention discloses a β-Ga₂O₃ nanowire / diamond heterostructure, its preparation method, and its applications. The method includes the following steps: dropping Ga metal droplets onto an auxiliary substrate; placing the diamond substrate and the auxiliary substrate in the same temperature zone of a tube furnace; introducing a mixed gas of H₂ and Ar into the tube furnace under negative pressure, using O₂ entering from the outside and residual O₂ in the tube furnace as the O source, and growing β-Ga₂O₃ nanowires on the diamond surface without catalysis. The method of this invention eliminates the need for additional annealing treatment and pre-laying of metal catalysts on the diamond substrate, and avoids the phenomenon of O₂ etching of the diamond substrate under high-temperature conditions. β-Ga₂O₃ nanowires are epitaxially grown on the diamond surface through the vapor deposition of Ga. This method is simple and low-cost.

The invention provides a method for growing and stripping polycrystalline diamond with low stress, the principle of the method is that the characteristic that a substrate and a transition layer are low in mismatch with the polycrystalline diamond is utilized, and meanwhile, the substrate is etched by hydrogen after the polycrystalline diamond grows by utilizing the strong etching capability of the hydrogen, so that the intervention of extra stress is avoided, and the polycrystalline fracture is reduced. Compared with the prior art, the scheme can effectively reduce the breakage of the polycrystalline diamond during stripping, and can be applied to solve the problem of low yield caused by breakage of the industrial MPCVD polycrystalline diamond.

The application discloses a deep-groove polysilicon etching solution, which comprises an oxidizing agent, an inorganic acid, a pH regulator and a surfactant. The deep-groove polysilicon etching solution can efficiently etch polysilicon while ensuring the uniformity and smoothness of the etching surface, and can maximize the consistency of the etching of the upper and lower grooves and the smoothness of the surface. In the etching process, the inorganic acid ensures that the etching solution system is in an acidic environment, and the polysilicon is etched; the pH regulator avoids the large fluctuation of the pH of the etching solution, thereby ensuring the stability of the polysilicon etching process; and the surfactant reduces the surface tension of the etching solution, improves the wettability of the etching solution, ensures the consistency of the etching rate of the upper and lower grooves, and ensures the consistency of the groove aperture.

The application discloses a fluorine-containing silicon nitride etching solution, which comprises phosphoric acid, a fluorine-containing compound, an aluminum oxide etching inhibitor, a tungsten etching inhibitor, a silicon oxide etching inhibitor and deionized water. The etching solution can realize selective etching of silicon nitride to silicon oxide, aluminum oxide and tungsten in hot phosphoric acid, while inhibiting etching of the silicon oxide, and the etching rate of the silicon nitride is more stable at high temperature than that of a phosphoric acid / hydrofluoric acid system due to the complexing and slow-release effect of the fluorine-containing compound.

The application relates to the field of optical communication technology, and particularly discloses a one-way coupling vertical grating coupler implementation method based on topological photonics; the method is based on an SOI platform, first, the size parameters of a uniform grating coupler are modeled and optimized; a single-etching rectangle in the grating is replaced by double-adjacent-rectangle etching to form a stepped structure, the up-down symmetry of the grating is destroyed, and the downward radiation is inhibited and the upward coupling is strengthened relying on the topological one-way coupling resonance principle; a super-Gaussian chirp function is introduced to modulate the etching width, the central period index, the envelope width and the super-Gaussian order are optimized, and the fiber mode field is matched; meanwhile, a waveguide and grating differential height design is adopted to expand the optimization space. The application does not need a DBR mirror and can be prepared only by surface etching, so the process is simplified; the grating to single-mode fiber coupling efficiency reaches 83.7%, the 3dB bandwidth is more than 79nm, and the application has the advantages of high coupling efficiency, wide bandwidth and high process fault tolerance.

The application relates to a semiconductor device and a preparation method thereof. The method comprises the following steps: providing a substrate; forming a plurality of first passivation layers arranged at intervals on the surface of the substrate; forming a plurality of ridges in the substrate, each ridge comprising part of the substrate, and each ridge having two sidewalls in the form of grooves formed in the substrate; wherein the first passivation layer is located on the ridge, and the total height of the first passivation layer and the ridge is greater than a height threshold; forming a second passivation layer on the surface of the substrate and the surface of each first passivation layer; forming a first photoresist layer on the surface of the second passivation layer; performing a patterning process on the first photoresist layer to expose the second passivation layer away from the first passivation layer and the second passivation layer on the ridge; and using a reflow process to make the first photoresist layer in each groove reflow along the sidewall of the ridge to cover the second passivation layer on the two sidewalls of the ridge. The application increases the height of the first passivation layer to improve the success rate of the reflow process, so that the reflow process is suitable for semiconductor devices with different ridge heights.

The invention discloses an electro-optical modulator and a preparation method thereof. The electro-optical modulator comprises an electro-optical material film wafer; the covering belt is arranged on the upper surface of the electro-optical material film wafer and is used for restraining a transverse electric mode; the traveling wave electrodes are arranged on the upper surface of the electro-optical material film wafer and located on the two sides of the covering belt. According to the invention, the preparation of the high-performance electro-optical modulator on the non-etching electro-optical material film is realized.