Method for depositing high insulating property SiO2 film with low-damage PECVD (Plasma Enhanced Chemical Vapor Deposition)

Abstract

The invention relates to a method for depositing high insulating property SiO2 film with low-damage PECVD (Plasma Enhanced Chemical Vapor Deposition), belonging to the technical field of photoelectronic device manufacturing, and particularly relating to a method for manufacturing a gallium nitride light emitting diode. The method comprises the following steps: leading N2O gas repeatedly for carrying out oxidation and purification treatments on the SiO2 film in the deposition process of the SiO2 film; reacting with dissociative Si ions existing on the surface of the SiO2 film by O ions generated after N2O ionization to generate SiO2; and reacting with dissociative H ions to generate H2O. The purity, the insulating property and the compactability of the SiO2 film are improved so that the cut-in voltage of the LED device is increased to more than 2.3v from about 2.1v. The method has the advantages of being little damaged for GaN substrate, low in radio-frequency power, high insulating property and compactability for deposited SiO2 film, and the like.

Description

technical field [0001] The invention belongs to the technical field of optoelectronic device manufacturing, and in particular relates to a gallium nitride (GaN)-based light-emitting diode (LED) manufacturing method. Background technique [0002] In the process of manufacturing GaN-based LED chips, there are three main processes: mesa etching, transparent electrode preparation, and PN metal electrode evaporation. Usually, the chip surface is finally covered with a layer of SiO 2 The thin film is used as a protective layer. On the one hand, the PN junction exposed on the side is covered with SiO 2 Protecting it can prevent the N electrode from being biased and touching the PN junction on the side wall during the process of encapsulating the gold wire, causing a short circuit of the LED, or metal particles falling on the PN junction of the side wall during use, causing a short circuit of the LED; On the one hand, indium tin oxide (ITO) is usually used as the transparent electr...

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Problems solved by technology

However, increasing the RF power will cause damage to the GaN luminescent material, resulting in an increase in the voltage of the LED device and a decrease in the luminous intensity.

However, if the method of reducing the RF power of PECVD is used to prepare SiO 2 thin film, SiO 2 The compactness and insulating properties of the film decrease, SiO 2 There will be a large number of unoxidized free Si ions on the surface of the film layer, which will cause the side wall PN junction to have a slight conduction phenomenon under low current, which will reduce the turn-on voltage of the LED (usually the turn-on voltage of the LED is greater than 2.1v), and the long-term reliability will be reduced.

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