Systems and methods for treating substrates with cryogenic fluid mixtures

Abstract

Disclosed herein are systems and methods for treating the surface of a microelectronic substrate, and in particular, relate to an apparatus and method for scanning the microelectronic substrate through a cryogenic fluid mixture used to treat an exposed surface of the microelectronic substrate. The fluid mixture may be expanded through a nozzle to form an aerosol spray or gas cluster jet (GCJ) spray may impinge the microelectronic substrate and remove particles from the microelectronic substrate's surface. In one embodiment, the fluid mixture may be maintained to prevent liquid formation within the fluid mixture prior to passing the fluid mixture through the nozzle. The fluid mixture may include nitrogen, argon, helium, neon, xenon, krypton, carbon dioxide, or any combination thereof.

1 - 20 . (canceled) 
     
     
         21 . A method for treating a microelectronic substrate to remove particles from a surface of the microelectronic substrate, comprising
 a) receiving the microelectronic substrate in a vacuum process chamber comprising a fluid expansion component comprising an inlet and an outlet, wherein the vacuum process chamber is at a pressure of 35 Torr or less;   b) positioning the substrate opposite the outlet of the fluid expansion component at a distance within 50 mm of the outlet;   c) supplying a pressurized and cooled incoming fluid or fluid mixture to the inlet of the fluid expansion component comprising:
 i) a controllable, incoming pressure greater than atmospheric pressure; and 
 ii) a controllable, incoming temperature that is less than 273K; 
   d) expanding the incoming fluid or fluid mixture into the vacuum process chamber through the outlet of the fluid expansion component to provide a spray that removes particles from the microelectronic substrate, wherein the controllable incoming pressure and controllable incoming temperature are controlled so that the spray has a particle removal efficiency that correlate to the controlled incoming temperature and pressure;   e) adjusting the incoming controllable temperature and/or incoming controllable pressure to control a phase composition of the incoming fluid or fluid mixture in a manner to alter the treatment spray that is provided when the incoming fluid or fluid mixture is expanded into the vacuum process chamber through the outlet of the fluid expansion component; and   f) using the altered treatment spray to remove particles from the microelectronic substrate.   
     
     
         22 . The method of  claim 21 , wherein the fluid or fluid mixture is argon. 
     
     
         23 . The method of  claim 21 , wherein the fluid or fluid mixture comprises argon and nitrogen. 
     
     
         24 . The method of  claim 21 , wherein the fluid or fluid mixture comprises a carrier gas. 
     
     
         25 . The method of  claim 21 , wherein step d) comprises controlling the incoming temperature and pressure so that the treatment spray has a desired particle removal efficiency for removing particles of a desired particle size. 
     
     
         26 . The method of  claim 25 , wherein step e) comprises changing the phase composition of the incoming fluid or fluid mixture. 
     
     
         27 . The method of  claim 25 , wherein step e) comprises altering the treatment spray to target and improve particle removal efficiency for particles having a smaller particle size. 
     
     
         28 . The method of  claim 21 , wherein the incoming fluid or fluid in steps c) and e) contains less than 1 weight percent of a liquid phase. 
     
     
         29 . The method of  claim 21 , wherein the pressure of the vacuum process chamber is less than 10 Torr. 
     
     
         30 . The method of  claim 21 , wherein the distance from the outlet to the surface of the microelectronic substrate is less than 10 mm. 
     
     
         31 . The method of  claim 21 , wherein the temperature and pressure of the incoming fluid or fluid mixture in step c) are controlled so that the treatment spray provides a particle removal efficiency for particles of a desired particle size. 
     
     
         32 . A method for treating a microelectronic substrate to remove particles of different sizes, comprising
 receiving the microelectronic substrate in a vacuum process chamber comprising a fluid expansion component comprising an inlet and an outlet, wherein the vacuum process chamber is at a pressure of 35 Torr or less;   positioning the substrate opposite the outlet of the fluid expansion component at a distance within 50 mm of the outlet;   supplying a pressurized and cooled incoming fluid or fluid mixture to the inlet of the fluid expansion component comprising:
 a controllable, incoming pressure greater than atmospheric pressure; and 
 a controllable, incoming temperature that is less than 273K; 
   expanding the incoming fluid or fluid mixture into the vacuum process chamber through the outlet of the fluid expansion component to provide a spray that removes particles from the microelectronic substrate, wherein the controllable incoming pressure and controllable incoming temperature are controlled so that the spray has a particle removal efficiency that correlate to the controlled incoming temperature and pressure and to target removal of particles having a desired particle size;   adjusting the temperature and/or pressure of the incoming fluid or fluid mixture in a manner effective to prevent formation of a liquid phase in the incoming fluid or fluid mixture and to alter the treatment spray that is provided when the incoming fluid or fluid mixture is expanded into the vacuum process chamber through the outlet of the fluid expansion component in a manner effective to target and improve particle removal efficiency of particles having a smaller particle size; and   using the altered treatment spray to remove particles from the microelectronic substrate.