Substrate processing method and substrate processing apparatus

Abstract

A wafer processing apparatus 100 is configured so that the number of repeated cycles of supplying pure water for maintaining the etching rate of phosphoric acid 10 to be high for the complete etching of the target film and halting the supply for each lot of wafers during a predetermined period of time, and, when the number of cycles falls outside a preset range of cycle counts, a notice to that effect is provided. Consequently, a lot of wafers having defective etching can be found with good accuracy, as well as defective etching being able to be prevented from occurring in subsequent lots of wafers.

1 . A substrate processing method comprising the steps of:
 immersing a substrate in a chemical solution stored in an etch tank;   heating the chemical solution;   repeating a cycle of starting supply of pure water to the etch tank while the chemical solution being heated when a temperature of the chemical solution reaches a value t 1  and halting the supply of pure water when the temperature of the chemical solution is lowered to a value t 2  (t 1 >t 2 ); and   counting the number of the cycles during a predetermined period of time;   wherein when the number of the cycles falls outside a preset range of cycle counts, a notice that the number of the cycles falling outside the preset range of the numbers is provided, and start of processing a substrate in a subsequent lot is halted.   
     
     
         2 . The substrate processing method according to  claim 1 , wherein the predetermined period of time excludes a period of time from a point of time when substrate processing is started and the substrate is immersed in the chemical solution to a point of time when the temperature of the chemical solution is increased to a set temperature. 
     
     
         3 . The substrate processing method according to  claim 1 , wherein the value ti is a boiling point of the chemical solution with a predetermined concentration, and a variation in a concentration of the chemical solution is kept within a predetermined range by keeping the temperature of the chemical solution within a range from the value t 1  to the value t 2 . 
     
     
         4 . A substrate processing apparatus in which a substrate is processing by being immersed in a chemical solution, the apparatus comprising:
 an etch tank that stores a chemical solution;   a heater that heats the chemical solution;   a temperature measuring unit that measures a temperature of the chemical solution in the etch tank;   a pure water supply unit that supplies pure water into the etch tank;   a controller that repeats a cycle of starting supply of pure water into the etch tank while the chemical solution being heated when the temperature measured by the temperature measuring unit reaches a value t 1  and halting the supply of pure water into the etch tank when the temperature is lowered to a value t 2  (t 1 >t 2 );   a counter that counts the number of the cycles during a predetermined period of time;   a notification unit that, when the number of the cycles counted by the counter falls outside a preset range of cycle counts, provides a notice that the number of the cycles falls outside of the preset range of the cycle counts; and   a halt unit that halts start of processing a substrate in a subsequent lot.   
     
     
         5 . The substrate processing apparatus according to  claim 4 , wherein the predetermined period of time excludes a period of time from a point of time when substrate processing is started and the substrate is immersed in the chemical solution to a point of time when the temperature of the chemical solution is increased to a set temperature. 
     
     
         6 . The substrate processing apparatus according to  claim 4 , wherein the value t 1  is a boiling point of the chemical solution with a predetermined concentration, and a variation in a concentration of the chemical solution is kept within a predetermined range by keeping the temperature of the chemical solution within a range from the value t 1  to the value t 2 .