Substrate processing control using a measured size distribution of by-product particles

1. A substrate processing method comprising:

heating a processing liquid including a chemical liquid and water to a predetermined first temperature higher than a boiling point of the water;

heating a substrate to a predetermined second temperature higher than the boiling point of the water;

supplying the processing liquid heated to the predetermined first temperature on the substrate heated to the predetermined second temperature in order to etch a material on the substrate so that a liquid layer maintained by surface tension is formed on the substrate;

etching the material from the substrate using a chemical reaction between the material and the processing liquid;

measuring a size distribution of by-product particles on a surface of the substrate formed by the chemical reaction between the material and the processing liquid; and

controlling a supply of the processing liquid based on the size distribution of the by-product particles,

wherein the controlling the supply of the processing liquid includes:

calculating an average size of the by-product particles from the size distribution of the by-product particles on the surface of the substrate;

cooling the substrate to a temperature lower than the boiling point of the water when the average size of the by-product particles is greater than a predetermined first size and smaller than a predetermined second size; and

replenishing the water on the substrate cooled to the temperature lower than the boiling point of the water.

2. The substrate processing method of claim 1 , wherein the size distribution of the by-product particles on the surface of the substrate is measured by dynamic light scattering.

3. The substrate processing method of claim 1 , wherein the controlling the supply of the processing liquid further comprises:

removing the liquid layer on the substrate when the average size of the by-product particles is greater than or equal to the predetermined second size; and

supplying the processing liquid on the substrate to form a second liquid layer.

4. The substrate processing method of claim 1 , wherein the controlling the supply of the processing liquid further comprises:

measuring a thickness of the liquid layer,

wherein the water is replenished so that the thickness of the liquid layer becomes a predetermined thickness.

5. The substrate processing method of claim 1 , wherein the substrate is rotated at a first speed within a range in which the liquid layer is maintained while etching the material.

6. The substrate processing method of claim 1 , wherein the substrate is rotated within a range in which the liquid layer is maintained while etching the material, and

a rotational speed of the substrate repeats acceleration and deceleration between a first speed and a second speed.

7. The substrate processing method of claim 1 , wherein the etching the material from the substrate comprises:

heating the substrate to a predetermined third temperature higher than the predetermined second temperature after the processing liquid is supplied onto the substrate.

8. The substrate processing method of claim 7 , wherein the controlling the supply of the processing liquid further comprises:

cooling the substrate to the second temperature when the average size of the by-product particles is greater than or equal to the predetermined second size;

rotating the substrate so that the liquid layer on the substrate is removed; and

supplying the processing liquid on the substrate to form the second liquid layer.

9. The substrate processing method of claim 1 , wherein the substrate is rotated at a first speed within a range in which the liquid layer is maintained while the water is replenished.

10. The substrate processing method of claim 1 , wherein the substrate is rotated within a range in which the liquid layer is maintained while the water is replenished; and

a rotational speed of the substrate repeats acceleration and deceleration between a first speed and a second speed.