Method and apparatus for multi-spray RRC process with dynamic control

A method, comprising:

• dispensing a first layer of solvent on a substrate while spinning at a first speed for a first time period such that the first layer of the solvent covers a first area of the substrate with a first radius and first thickness;
• dispensing the solvent on the substrate while spinning at a second speed for a second time period following the first time period so as to transform the first layer to a second layer of the solvent such that the second layer of the solvent covers a second area of the substrate with a second radius and second thickness;
• dispensing the solvent on the substrate while spinning so as to transform the second layer to a third layer of the solvent such that the third layer of the solvent covers a third area of the substrate with a third radius and a third thickness;
• dispensing the solvent on the substrate while spinning at a third speed for a third time period following the second time period so as to transform the third layer to a fourth layer of the solvent such that the fourth layer of the solvent covers a fourth area of the substrate with a fourth radius and fourth thickness, wherein the first and second radii are substantially equal to each other and each less than each of the third and fourth radii, and wherein the first and third thicknesses are substantially equal to each other and each less than each of the second and fourth thicknesses;
• dispensing the solvent on the substrate while spinning at a fourth speed for a fourth time period following the third time period so as to transform the fourth layer to a fifth layer of the solvent;
• dispensing a first layer of photoresist on the fifth layer of the solvent while spinning at a fifth speed for a fifth period of time following the fourth time period,
• wherein the second speed is less than the first speed and the third speed is greater than the first speed, the fourth speed is less than the second speed and the fifth speed is less than the fourth speed.

A method, comprising:

• dispensing a first layer of solvent on a substrate while spinning at a first speed for a first time period such that the first layer of the solvent covers a first area of the substrate with a first radius and a first thickness;
• dispensing the solvent on the substrate while spinning at a second speed for a second time period following the first time period so as to transform the first layer to a second layer of the solvent such that the second layer of the solvent covers a second area of the substrate with a second radius and a second thickness;
• dispensing the solvent on the substrate while spinning at a third speed for a third time period following the second time period so as to transform the second layer to a third layer of the solvent such that the third layer of the solvent covers a third area of the substrate with a third radius and a third thickness;
• dispensing the solvent on the substrate while spinning at a fourth speed for a fourth time period following the third time period so as to transform the third layer to a fourth layer of the solvent such that the fourth layer of the solvent covers a fourth area of the substrate with a fourth radius and fourth thickness, wherein the first and second radii are substantially equal to each other and each different from the third and fourth radii, and wherein the first and third thicknesses are substantially equal to each other and each different from each of the second and fourth thicknesses;
• and
• dispensing a first layer of photoresist on the fourth layer of the solvent while spinning at a fifth speed for a fifth period of time,
• wherein the third speed is greater than the first speed, wherein the first speed is greater than the second speed, and wherein the second speed is greater than the fourth speed, wherein the first time period and the third time period are each greater than each of the second time period and the fourth time period.