Temperature control method

Abstract

A temperature control method of controlling a temperature of a semiconductor wafer mounted on a mounting table includes a supply process of supplying, in a state that a supply of a power to a heater configured to heat the mounting table is stopped or the power is maintained to be constant, a heat transfer gas into a gap between the semiconductor wafer and the mounting table; a measurement process of measuring a temperature variation of the mounting table due to heat exchange between the semiconductor wafer and the mounting table through the heat transfer gas; a calculation process of calculating a correction value based on the temperature variation of the mounting table; and a control process of starting the supply of the power and controlling the power such that the temperature of the mounting table reaches a target temperature corrected with the correction value.

We claim: 
     
         1 . A temperature control method comprising:
 (a) providing a substrate on a substrate support surface of a substrate support, the substrate having a temperature different from a temperature of the substrate support;   (b) supplying, in a state that a supply of a power to at least one heater configured to heat the substrate support is stopped or in a state that the power supplied to the at least one heater is maintained to be constant, a heat transfer gas into a gap between a rear surface of the substrate and the substrate support surface through one or more supply holes positioned within the substrate support surface;   (c) measuring a temperature variation of the substrate support due to heat exchange between the substrate and the substrate support through the heat transfer gas;   (d) calculating a correction value based on the temperature variation of the substrate support; and   (e) controlling the power to the at least one heater such that the temperature of the substrate support reaches a target temperature corrected with the correction value.   
     
     
         2 . The temperature control method of  claim 1 ,
 wherein, in (c), a gradient of the temperature variation of the substrate support in a time period between a first time point upon the lapse of a first time after the heat transfer gas is supplied into the gap between the rear surface of the substrate and the substrate support surface of the substrate support and a second time point upon the lapse of a second time from the first time point is measured as the temperature variation of the substrate support.   
     
     
         3 . The temperature control method of  claim 2 , further comprising:
 (c-1) measuring, after supplying, in the state that the supply of the power to the at least one heater configured to heat the substrate support is stopped or in the state that the power supplied to the at least one heater is maintained to be constant, the heat transfer gas into the gap between a temperature measurement wafer having a temperature different from the temperature of the substrate support and the substrate support on which the temperature measurement wafer is mounted and after measuring the temperature variation of the substrate support due to heat exchange between the temperature measurement wafer and the substrate support through the heat transfer gas, the temperature of the temperature measurement wafer by controlling the power to the at least one heater such that the temperature of the substrate support reaches a preset temperature; and   (c-2) creating a correction table in which, for each of different pressures of the heat transfer gas, the temperature variation of the substrate support measured in (c-1) corresponds to the correction value according to a difference between the temperature of the temperature measurement wafer measured in (c-1) and a reference temperature,   wherein the correction value based on the temperature variation of the substrate support is calculated from the correction table in (d).   
     
     
         4 . The temperature control method of  claim 1 ,
 wherein (b), (c), (d) and (e) are performed on the substrate before the substrate is processed.   
     
     
         5 . The temperature control method of  claim 1 ,
 wherein the heat transfer gas is supplied into the gap between the rear surface of the substrate and the substrate support surface of the substrate support through multiple supply holes formed in the substrate support surface of the substrate support.   
     
     
         6 . The temperature control method of  claim 1 ,
 wherein the at least one heater is plural in number, and   the heaters are provided within the substrate support in concentric shapes having different radii when viewed from above the substrate support.   
     
     
         7 . The temperature control method of  claim 6 ,
 wherein the correction value based on the temperature variation of the substrate support is calculated for each of the heaters in (d), and   the power to each of the heaters is controlled such that the temperature of the substrate support reaches the target temperature in (e).   
     
     
         8 . A temperature control method comprising:
 (a) cooling a substrate support on which a substrate is supported;   (b) providing the substrate on a substrate support surface of the substrate support;   (c) supplying a heat transfer gas into a gap between a rear surface of the substrate and the substrate support surface through one or more supply holes positioned within the substrate support surface;   (d) measuring a temperature variation of the substrate support after (c);   (e) calculating a correction value based on the temperature variation of the substrate support; and   (f) controlling a temperature of the substrate support to reach a target temperature corrected with the correction value.   
     
     
         9 . The temperature control method of  claim 8 ,
 wherein, in (c), the supplying of the heat transfer gas is started in a state that a supply of a power to at least one heater configured to heat the substrate support is stopped or in a state that the power supplied to the at least one heater is maintained to be constant.   
     
     
         10 . The temperature control method of  claim 8 ,
 wherein, in (f), the temperature of the substrate support is controlled to reach a target temperature corrected with the correction value by controlling the supply of the power to the at least one heater and/or a pressure of the heat transfer gas.   
     
     
         11 . The temperature control method of  claim 8 ,
 wherein the substrate support has multiple zones,   the at least one heater is provided in each of the multiple zones, and   (c), (d), (e) and (f) are performed for each of the multiple zones.   
     
     
         12 . The temperature control method of  claim 11 ,
 wherein the multiple zones of the substrate support have concentric shapes having different radii.   
     
     
         13 . The temperature control method of  claim 11 ,
 wherein the substrate support has at least one temperature sensor for each of the multiple zones.   
     
     
         14 . A plasma processing method comprising:
 (a) cooling a substrate support on which a substrate is supported;   (b) providing the substrate on a substrate support surface of the substrate support;   (c) supplying a heat transfer gas into a gap between a rear surface of the substrate and the substrate support surface through one or more supply holes positioned within the substrate support surface;   (d) measuring a temperature variation of the substrate support after (c);   (e) calculating a correction value based on the temperature variation of the substrate support;   (f) controlling a supply of a power to at least one heater configured to heat the substrate support and/or a pressure of the heat transfer gas such that a temperature of the substrate support reaches a target temperature corrected with the correction value; and   (g) plasma-processing the substrate after the temperature of the substrate support is stabilized;   
     
     
         15 . The plasma processing method of  claim 14 ,
 wherein, in (c), the supplying of the heat transfer gas is started in a state that the supply of the power to the at least one heater is stopped or in a state that the power supplied to the at least one heater is maintained to be constant.   
     
     
         16 . The plasma processing method of  claim 14 ,
 wherein the substrate support has multiple zones,   the at least one heater is provided in each of the multiple zones, and   (c), (d), (e) and (f) are performed for each of the multiple zones.