Gas injection system for energetic-beam instruments

Abstract

A gas injection system for an energetic-beam instrument having a vacuum chamber. The system has a cartridge containing a chemical serving as a source for an output gas to be delivered into the vacuum chamber. The cartridge has a reservoir containing the chemical, which rises to a fill line having a level defined by an amount of the chemical present in the reservoir at a given time. An outlet from the reservoir is coupled to an output passage through an outlet valve and configured so that when the system is tilted the outlet remains above the level of the fill line. Embodiments include isolation valves allowing the cartridge to be disconnected without destroying system vacuum.

We claim:  
     
         1 . A gas injection system for an energetic-beam instrument having a vacuum chamber, the gas injection system comprising:
 a cartridge capable of containing a chemical serving as a source for an output gas to be delivered into the vacuum chamber;   a recognition device for reading information about the cartridge; and   an identification device attached to the cartridge and having coded information regarding one or more characteristics of the cartridge; the identification device communicably connected to the recognition device, such that the identification device supplies the coded information to the recognition device; and;   a controller communicably connected to the recognition device, the controller configured such that it is capable of varying a deposition parameter of the gas injection system, whereby operation of the gas injection system may be controlled in response to the coded information.   
     
     
         2 . The gas injection system of  claim 1 , further comprising a sensor capable of sensing a pressure within the vacuum chamber communicably connected to the controller, whereby the gas injection system may be controlled in response to the pressure. 
     
     
         3 . The gas injection system of  claim 1 , further comprising:
 a sensor capable of sensing a composition of an atmosphere within the vacuum chamber; the sensor communicably connected to the controller, whereby the gas injection system may be controlled in response to the composition.   
     
     
         4 . The gas injection system of  claim 3 , wherein the sensor is a residual gas analyzer. 
     
     
         5 . The gas injection system of  claim 3 , wherein the sensor is an optical spectrometer. 
     
     
         6 . The gas injection system of  claim 1 , the cartridge further comprising
 a reservoir containing the chemical, the chemical rising to a fill line; the fill line having a level defined by an amount of the chemical present in the reservoir at a given time; and,   an outlet from the reservoir removably coupled to the delivery path; the outlet disposed in the reservoir at a level above the level of the fill line and configured so that as the gas injection system is tilted to a tilt angle, the outlet remains above the level of the fill line, whereby the chemical is prevented from entering the vacuum chamber while the output gas is being delivered.   
     
     
         7 . A gas injection system for an energetic-beam instrument having a vacuum chamber, the gas injection system comprising:
 a chassis mounted to the vacuum chamber;   a removable cartridge supported upon the chassis and having an interior and an exterior, and capable of containing a chemical serving as a source for an output gas, the removable cartridge comprising an output passage through which the output gas may flow from the interior to the exterior of the cartridge;   a delivery path having a conductance and connecting the output passage of the removable cartridge to the vacuum chamber, through which the output gas is delivered into the vacuum chamber; and   an isolation valve in the delivery path between the cartridge and the vacuum chamber, whereby the cartridge may be removed while the vacuum chamber remains under vacuum when the isolation valve is closed.   
     
     
         8 . The gas injection system of  claim 7 , wherein the removable cartridge further comprises an output valve. 
     
     
         9 . The gas injection system of  claim 8 , wherein the output valve further comprises an output metering valve. 
     
     
         10 . The gas injection system of  claim 7 , wherein the delivery path further comprises a manifold. 
     
     
         11 . The gas injection system of  claim 10 , wherein the isolation valve comprises an isolation valve in the manifold associated with the removable cartridge, whereby the cartridge may be removed while the vacuum chamber remains under vacuum when the associated isolation valve is closed. 
     
     
         12 . The gas injection system of  claim 7 , wherein the removable cartridge further comprises an input valve. 
     
     
         13 . The gas injection system of  claim 7 , wherein the delivery path terminates in a nozzle for injecting the output gas into the vacuum chamber; the nozzle having a location in the vacuum chamber. 
     
     
         14 . The gas injection system of  claim 13 , further comprising an actuator coupled to the nozzle for controlling the location of the nozzle within the vacuum chamber. 
     
     
         15 . The gas injection system of  claim 7 , further comprising:
 a recognition device for reading information about the removable cartridge; and   an identification device attached to the removable cartridge and having coded information regarding one or more characteristics of the cartridge, the identification device communicably connected to the recognition device, such that the identification device supplies the coded information to the recognition device.   
     
     
         16 . The gas injection system of  claim 7 , further comprising a controller configured such that it is capable of varying a parameter of the gas injection system, whereby the operation of the gas injection system may be controlled. 
     
     
         17 . The gas injection system of  claim 16 , wherein the controller further comprises a programmable computer. 
     
     
         18 . The gas injection system of  claim 16 , further comprising:
 a recognition device for reading information about the removable cartridge communicably connected to the controller; and   an identification device attached to the removable cartridge and having coded information regarding one or more characteristics of the cartridge, the identification device communicably connected to the recognition device, such that the identification device supplies the coded information to the recognition device, whereby the gas injection system may be controlled in response to the coded information.   
     
     
         19 . The gas injection system of  claim 16 , further comprising a sensor capable of sensing a pressure within the vacuum chamber communicably connected to the controller, whereby the gas injection system may be controlled in response to the pressure. 
     
     
         20 . The gas injection system of  claim 16 , further comprising:
 a sensor capable of sensing a composition of an atmosphere within the vacuum chamber; the sensor communicably connected to the controller, whereby the gas injection system may be controlled in response to the composition.   
     
     
         21 . The gas injection system of  claim 7 , the removable cartridge further comprising
 a reservoir containing the chemical, the chemical rising to a fill line; the fill line having a level defined by an amount of the chemical present in the reservoir at a given time; and,   an outlet from the reservoir removably coupled to the delivery path; the outlet disposed in the reservoir at a level above the level of the fill line and configured so that as the gas injection system is tilted to a tilt angle, the outlet remains above the level of the fill line, whereby the chemical is prevented from entering the vacuum chamber while the output gas is being delivered.   
     
     
         22 . The gas injection system of  claim 21 , wherein the removable cartridge further comprises an output valve. 
     
     
         23 . The gas injection system of  claim 7 , further comprising:
 an evacuation path having a higher conductance than the delivery path and connecting the delivery path to a source of vacuum; and   a purge valve capable of opening or closing the evacuation path, whereby the delivery path can be evacuated when the purge valve is opened.   
     
     
         24 . The gas injection system of  claim 23 , wherein the source of vacuum is the vacuum chamber of the energetic beam instrument. 
     
     
         25 . A method of supplying a gas to a vacuum chamber, the method comprising:
 providing a cartridge enclosing a source of a gas, where the cartridge has at least one delivery path having a conductance and selectively openable to the vacuum chamber;   removably connecting the cartridge to the vacuum chamber while keeping the chamber under vacuum;   identifying one or more characteristics of the cartridge automatically; and   controlling a flow of the gas from the cartridge into the vacuum chamber according to the identified characteristics of the cartridge.   
     
     
         26 . The method of  claim 25 , wherein the step of identifying further comprises transmitting the identified characteristics of the cartridge to a controller. 
     
     
         27 . The method of  claim 26 , further comprising:
 connecting the controller to a sensor capable of sensing a pressure inside the vacuum chamber; and   controlling the flow of the gas in response to a signal from the sensor.   
     
     
         28 . The method of  claim 25 , further comprising a step of evacuating the at least one delivery path through an evacuation path having a conductance higher than the conductance of the delivery path. 
     
     
         29 . The method of  claim 25 , further comprising:
 recognizing the amount of time since the cartridge was last used; and, controllably releasing the pressure in the cartridge into the vacuum chamber as a function of this time duration.