Tray device for etching patterned sapphire substrate and loading method

Abstract

The invention discloses a tray device for etching a patterned sapphire substrate and a loading method. The tray device comprises a tray body, wherein a locating groove for fixing the sapphire substrate is formed in the upper surface of the tray body; the upper surface of the tray body and the surface of the locating groove are coated with heat conduction medium layers; the locating groove is 100 to 300 microns deep and 105 to 110 millimeters wide; a sinking region is arranged on the edge of the tray body; a height difference between the sinking region and the upper surface of the tray body is2 to 5 millimeters. The tray device improves the convenience in operation and effectively guarantees the manufacturing stability and the product yield of a PSS process.

Description

technical field [0001] The invention belongs to the technical field of semiconductor processing, in particular to a tray device and a loading method for patterned sapphire substrate etching. Background technique [0002] Patterned Sapphire Substrates (PSS) is an effective method adopted by the industry to improve the luminous efficiency of GaN-based LED devices. At present, PSS is mainly prepared by photolithography technology combined with plasma (ICP) dry etching technology. Usually, during the plasma dry etching process of the sapphire substrate, a tray device is generally used to fix, support and transport the sapphire substrate into the cavity of the ICP equipment, so as to avoid the movement or dislocation of the sapphire substrate during the etching process . In addition, during the whole process, the tray acts as the lower electrode of the electrode system. By connecting the radio frequency (RF) power, the RF power will form a DC bias (DC Bias) on the surface of th...

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Problems solved by technology

[0005] (1) Since the edge of the sapphire substrate is adjacent to the cover plate, and the pressing claws of the cover plate directly cover the substrate surface, the plasma electric field distribution is affected by the edge effect of the cover plate during the etching process, resulting in the edge area of ​​the PSS finished product The microstructure graphics are distorted, and the bottom diameters of the graphics are connected together to form a wide invalid transition zone (such as image 3 shown), which directly affects the utilization rate of LED chips in the edge area after PSS epitaxy;

[0006] (2) In the process of loading the sapphire substrate into the tray device, a series of actions such as fixing the sealing ring, aligning the sapphire with the tray boss, placing the cover plate, and tightening the fixing screws are required. The operation process is relatively complicated and requires high precision. , the requirements for operators are extremely high, and it is easy to cause yield loss due to human error;

[0007] (3) Since the cover plate is exposed in the ICP cavity, it is continuously worn out during the etching process, resulting in a shortened service life of the cover plate, which is not conducive to the cost control of PSS products. In addition, the later part of the service cycle of the cover plate is due to the wear of the pressure claws , The probability of yield drop caused by deformation gradually increases;

[0008] (4) During the entire etching process of the sapphire substrate, the requirements for the accessories of the tray device are extremely high. The material and size deviation of the sealing ring and the size of the cover plate's pressing claw are the relevant factors affecting the leakage of He gas. The leakage of He gas will It will cause the local temperature of the wafer to be too high, which will lead to the distortion of the microstructure pattern on the wafer surface. The existing aluminum tray system has very high requirements on the wafer loading and sealing, and the operable process window is narrow.

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