Cleaning process for epi-ready sapphire wafer

Abstract

The invention discloses a cleaning process for an epi-ready sapphire wafer. The cleaning process comprises the following steps of: firstly performing ultrasonic vibratory cleaning on the sapphire wafer more than once by using a cleaning agent and ultrapure water so as to remove dirt and fine particles on the surface of the wafer; secondly, brushing the wafer so as to remove large particles on thesurface of the wafer; then spraying an emulsifying agent to the wafer so as to control the adsorption state of the surface of the wafer; then spraying an organic solvent to the wafer so as to avoid the secondary adsorption of contaminants; and finally drying the wafer by using a spin dryer, keeping the wafer still and drying the wafer. When the sapphire wafer cleaned by the cleaning process is putinto the PSS production, the relatively high yield of finished products can be obtained under the condition of directly using the wafer.

Description

technical field

[0001] The invention relates to the technical field of sapphire processing, in particular to a sapphire wafer cleaning process that can be used out of the box. Background technique

[0002] At present, sapphire has been widely used as the substrate material for making GaN-based LED chips on the market. However, due to the large lattice mismatch thermal expansion coefficient difference between nitride and sapphire, the nitride material grown on the substrate has dislocations and defects. The high density affects the luminous efficiency and life of the device. The patterned substrate (PSS) technology can effectively reduce the dislocations and defects of epitaxial materials, and is widely used in the preparation of nitride devices.

[0003] In PSS production, if there is contamination or metal ions on the surface of the sapphire wafer, in the photolithography process, the impurities will cause uneven coating and poor wetting, resulting in unclear images, change...

Examples

Embodiment 1

[0058] Step 1: Put the sapphire wafer that has been polished on one side into the process wafer box, and place the process wafer with the wafer in the pure water tank;

[0059] Step 2: Put the sapphire wafer processed in step 1 into the first alkaline cleaning agent for cleaning, the concentration of the cleaning agent is 10wt%, the temperature in the tank is 55°C, and the wafer is rotated 90° after every ten times of throwing up and down before continuing Throwing, each cleaning time is 25min, a total of four times;

[0060] Step 3: Put the sapphire wafer processed in Step 2 into the first ultrapure water for ultrasonic rinsing, the temperature in the tank is 20°C, the ultrasonic intensity is 40KHz, and the cleaning time is 15 minutes;

[0061] Step 4: Put the sapphire wafer processed in Step 3 into the second cleaning agent solution for cleaning. The cleaning agent concentration is 10wt%, the temperature in the tank is 55°C, and the wafer is rotated 90° after every ten times...

Embodiment 2

[0071] Step 1: Put the sapphire wafer that has been polished on one side into the process wafer box, and place the process wafer with the wafer in the pure water tank;

[0072] Step 2: Put the sapphire wafer processed in step 1 into the first alkaline cleaning agent for cleaning, the concentration of the cleaning agent is 20wt%, the temperature in the tank is 75°C, and the wafer is rotated 90° after every ten times of throwing up and down before continuing Throwing, each cleaning time is 15min, a total of four times;

[0073] Step 3: Put the sapphire wafer processed in Step 2 into the first ultrapure water for ultrasonic rinsing, the temperature in the tank is 30°C, the ultrasonic intensity is 40KHz, and the cleaning time is 35 minutes;

[0074] Step 4: Put the sapphire wafer processed in Step 3 into the second cleaning agent solution for cleaning. The cleaning agent concentration is 20wt%, the temperature in the tank is 75°C, and the wafer is rotated 90° after every ten times...

Embodiment 3

[0084] Step 1: Put the sapphire wafer that has been polished on one side into the process wafer box, and place the process wafer with the wafer in the pure water tank;

[0085] Step 2: Put the sapphire wafer processed in step 1 into the first alkaline cleaning agent for cleaning, the concentration of the cleaning agent is 15wt%, the temperature in the tank is 65°C, and the wafer is rotated 90° after every ten times of throwing up and down before continuing Throwing, each cleaning time is 20min, a total of four times;

[0086] Step 3: Put the sapphire wafer processed in Step 2 into the first ultrapure water for ultrasonic rinsing, the temperature in the tank is 25°C, the ultrasonic intensity is 40KHz, and the cleaning time is 20 minutes;

[0087] Step 4: Put the sapphire wafer processed in step 3 into the second cleaning agent solution for cleaning. The cleaning agent concentration is 15wt%, the temperature in the tank is 65°C, and the wafer is rotated 90° after every ten times...

technical field

[0001] The invention relates to the technical field of sapphire processing, in particular to a sapphire wafer cleaning process that can be used out of the box. Background technique

[0002] At present, sapphire has been widely used as the substrate material for making GaN-based LED chips on the market. However, due to the large lattice mismatch thermal expansion coefficient difference between nitride and sapphire, the nitride material grown on the substrate has dislocations and defects. The high density affects the luminous efficiency and life of the device. The patterned substrate (PSS) technology can effectively reduce the dislocations and defects of epitaxial materials, and is widely used in the preparation of nitride devices.

[0003] In PSS production, if there is contamination or metal ions on the surface of the sapphire wafer, in the photolithography process, the impurities will cause uneven coating and poor wetting, resulting in unclear images, change...

Examples

Embodiment 1

[0058] Step 1: Put the sapphire wafer that has been polished on one side into the process wafer box, and place the process wafer with the wafer in the pure water tank;

[0059] Step 2: Put the sapphire wafer processed in step 1 into the first alkaline cleaning agent for cleaning, the concentration of the cleaning agent is 10wt%, the temperature in the tank is 55°C, and the wafer is rotated 90° after every ten times of throwing up and down before continuing Throwing, each cleaning time is 25min, a total of four times;

[0060] Step 3: Put the sapphire wafer processed in Step 2 into the first ultrapure water for ultrasonic rinsing, the temperature in the tank is 20°C, the ultrasonic intensity is 40KHz, and the cleaning time is 15 minutes;

[0061] Step 4: Put the sapphire wafer processed in Step 3 into the second cleaning agent solution for cleaning. The cleaning agent concentration is 10wt%, the temperature in the tank is 55°C, and the wafer is rotated 90° after every ten times...

Embodiment 2

[0071] Step 1: Put the sapphire wafer that has been polished on one side into the process wafer box, and place the process wafer with the wafer in the pure water tank;

[0072] Step 2: Put the sapphire wafer processed in step 1 into the first alkaline cleaning agent for cleaning, the concentration of the cleaning agent is 20wt%, the temperature in the tank is 75°C, and the wafer is rotated 90° after every ten times of throwing up and down before continuing Throwing, each cleaning time is 15min, a total of four times;

[0073] Step 3: Put the sapphire wafer processed in Step 2 into the first ultrapure water for ultrasonic rinsing, the temperature in the tank is 30°C, the ultrasonic intensity is 40KHz, and the cleaning time is 35 minutes;

[0074] Step 4: Put the sapphire wafer processed in Step 3 into the second cleaning agent solution for cleaning. The cleaning agent concentration is 20wt%, the temperature in the tank is 75°C, and the wafer is rotated 90° after every ten times...

Embodiment 3

[0084] Step 1: Put the sapphire wafer that has been polished on one side into the process wafer box, and place the process wafer with the wafer in the pure water tank;

[0085] Step 2: Put the sapphire wafer processed in step 1 into the first alkaline cleaning agent for cleaning, the concentration of the cleaning agent is 15wt%, the temperature in the tank is 65°C, and the wafer is rotated 90° after every ten times of throwing up and down before continuing Throwing, each cleaning time is 20min, a total of four times;

[0086] Step 3: Put the sapphire wafer processed in Step 2 into the first ultrapure water for ultrasonic rinsing, the temperature in the tank is 25°C, the ultrasonic intensity is 40KHz, and the cleaning time is 20 minutes;

[0087] Step 4: Put the sapphire wafer processed in step 3 into the second cleaning agent solution for cleaning. The cleaning agent concentration is 15wt%, the temperature in the tank is 65°C, and the wafer is rotated 90° after every ten times...