Method and apparatus for warming up a vacuum pump arrangement

Abstract

A method for warming up a vacuum pump arrangement having a booster pump and a backing pump downstream of the booster pump for evacuating a process chamber includes setting the booster pump at a first speed higher than an idle speed of the booster pump when the same is in an idle mode; and controlling a backing pressure at an outlet of the booster pump within a range from 0.1 mbar to 10 mbar at least for a period of time from when the vacuum pump arrangement is activated from the idle mode to when the booster pump reaches a temperature equal to or exceeding a first predetermined threshold value. Such method is implemented in system where a controlled is configured to carry out the above-motioned actions.

1 . A method for warming up a vacuum pump arrangement having a booster pump and a backing pump downstream of the booster pump for evacuating a process chamber, comprising:
 setting the booster pump at a first speed higher than an idle speed of the booster pump when the booster pump is in an idle mode; and   controlling a backing pressure at an outlet of the booster pump within a range from 0.1 millibar to 10 millibar at least for a period of time from when the vacuum pump arrangement is activated from the idle mode to when the booster pump reaches a temperature equal to or exceeding a first predetermined threshold temperature value.   
     
     
         2 . The method of  claim 1 , wherein the controlling a backing pressure comprising adjusting a speed of the backing pump, wherein an inlet of the backing pump is connected to the outlet of the booster pump. 
     
     
         3 . The method of  claim 2 , wherein the backing pump is set at a second speed when the vacuum pump arrangement is activated from the idle mode. 
     
     
         4 . The method of  claim 3 , wherein the second speed of the backing pump is decreased to a predetermined level in order for the backing pressure of the booster pump to fall within the range from 0.1 millibar to 10 millibar. 
     
     
         5 . The method of  claim 4 , wherein the second speed is decreased to the predetermined level incrementally over a number of time intervals. 
     
     
         6 . The method of  claim 1 , wherein the controlling the backing pressure comprising injecting a purge gas at the outlet of the booster pump. 
     
     
         7 . The method of  claim 6 , wherein a flow rate of the purge gas is controlled in a manner that the backing pressure of the booster pump is adjusted into the range from 0.1 millibar to 10 millibar. 
     
     
         8 . The method of  claim 1 , wherein the vacuum pump arrangement is set to be ready for evacuating the process chamber in a normal operation mode when the temperature of the booster pump is equal to or exceeds the first predetermined threshold value and a temperature of the backing pump is equal to or exceeds a second predetermined threshold value. 
     
     
         9 . An apparatus comprising:
 a process chamber;   a booster pump having an inlet fluidly connected to an outlet of the process chamber;   a backing pump having an inlet fluidly connected to an outlet of the booster pump for, together with the booster pump, evacuating the process chamber; and   a controller electrically coupled with the booster pump and the backing pump, the controller being configured to control a backing pressure at the outlet of the booster pump within a range from 0.1 millibar to 10 millibar at least for a period of time from when the booster pump and the backing pump are activated from an idle mode to when the booster pump reaches a temperature equal to or exceeding a first predetermined threshold value.   
     
     
         10 . The apparatus of  claim 9 , wherein the controller is configured to control the backing pressure of the booster by adjusting a speed of the backing pump. 
     
     
         11 . The apparatus of  claim 10 , wherein the controller is configured to set the backing pump at a predetermined speed when the vacuum pump arrangement is activated from the idle mode. 
     
     
         12 . The apparatus of  claim 11 , wherein the controller is configured to reduce the predetermined speed of the backing pump to a predetermined level in order for the backing pressure of the booster pump to fall within into the range from 0.1 millibar to 10 millibar. 
     
     
         13 . The apparatus of  claim 12 , wherein the controller is configured to reduce the predetermined speed to the predetermined level incrementally over a number of time intervals. 
     
     
         14 . The apparatus of  claim 9 , further comprising a source of purge gas fluidly connected at the outlet of the booster pump. 
     
     
         15 . The apparatus of  claim 14 , wherein the controller is configured to control a flow rate of a purge gas being injected at the outlet of the booster pump, thereby controlling the backing pressure of the booster pump within the range from 0.1 millibar to 10 millibar. 
     
     
         16 . The apparatus of  claim 9 , wherein the booster pump and the backing pump are set to be ready for evacuating the process chamber in a normal operation mode when the temperature of the booster pump is equal to or exceeds the first predetermined threshold value and a temperature of the backing pump is equal to or exceeds a second predetermined threshold value.