Semiconductor structure and forming method thereof

Abstract

The invention provides a semiconductor structure and a forming method thereof. The method comprises the following steps: providing a substrate; forming a first nitride semiconductor layer on the substrate; etching the first nitride semiconductor layer to form a plurality of openings; etching the first nitride semiconductor layer from the openings to form a plurality of holes or slots, which extend to the top surface or the interior of the substrate; performing corrosion treatment of the substrate through the plurality of holes or slots to form a plurality of support structures; and depositing a nitride semiconductor material, realizing cross growth at the exposed part of the first nitride semiconductor layer in the plurality of holes or slots so as to fill the plurality of holes or slots, and after that, continually realizing epitaxial growth to form a second nitride semiconductor layer on the first nitride semiconductor layer. By adopting the method, the dislocation density of a semiconductor can be reduced, the growth quality of a thin film is improved, and cost reduction and substrate stripping in the later period are facilitated.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a semiconductor structure and a forming method thereof. Background technique [0002] In recent years, LEDs have been widely used in display screens, backlights, lighting and other fields due to their long life, high luminous efficiency, small size, durability, and rich colors. The core of the LED device is the LED epitaxial wafer. How to obtain a high-quality, low-defect-density nitride semiconductor epitaxial material film on a suitable substrate is the most critical factor for improving the luminous efficiency and life of the LED. However, due to the characteristics of the nitride semiconductor epitaxial material film itself, it is different from the commonly used SiC, Al 2 o 3 Substrates, especially low-cost Si substrates, have relatively large lattice mismatch and thermal mismatch. Therefore, if a nitride semiconductor epitaxial material film is directl...

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Problems solved by technology

However, due to the characteristics of the nitride semiconductor epitaxial material film itself, it is different from the commonly used SiC, Al 2 o 3 Substrates, especially low-cost Si substrates, have relatively large lattice mismatch and thermal mismatch. Therefore, if a nitride semiconductor epitaxial material film is directly epitaxy on these substrates, a large number of punching dislocations will be generated. As a result, the epitaxial nitride semiconductor film has a large dislocation density, and severe thermal mismatch can also cause cracks in the epitaxial film, which seriously affects the performance of the prepared LED device.

In order to reduce the dislocation density of the epitaxial nitride semiconductor film, a method of using the lateral growth characteristics of the nitride semiconductor material to reduce the dislocation density of the epitaxial film has been developed. It is relatively low, but there are still a large number of punching dislocations in the epitaxial material in the non-lateral epitaxial region, and the problem of cracking of the epitaxial film caused by thermal mismatch is not solved, which will still seriously affect the performance of the prepared device

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