Plasma processing apparatus

Abstract

A plasma processing apparatus for processing a specimen placed on a table disposed inside of a processing chamber by using plasmas formed in the processing chamber in which the table is disposed. A first member is placed in contact with the specimen and a second member is disposed below the first member. A temperature control device is disposed inside the table for controlling the temperature of the outer circumferential zone and the central zone of the table to first and second temperatures, respectively. A pressure control device is also provided for controlling pressure between the surface of the table and the specimen.

1 . A plasma processing method comprising the steps of locating a specimen on a specimen table having a heat conductive member and provided inside of a processing chamber; supplying a processing gas during evacuation of an inside the processing chamber from a lower portion thereof; and generating plasma inside of the processing chamber so as to process the specimen; 
 wherein the specimen table comprises a ring-like protrusion having a convex part disposed on an upper surface of the specimen table and at a position between a central portion and an outer circumferential portion of the specimen table, the ring-like protrusion contacting a rear surface of the specimen so as to delimit a central part space and a circumferential part space between the specimen rear surface and the upper surface of the specimen tables the spaces being independent of one another;    the method further comprising the steps of:    circulating cooling mediums inside each of a central passage disposed in a central portion of the heat conductive member of the specimen table and a circumferential passage disposed in a circumferential portion of the heat conductive member, wherein the central passage and the circumferential passage are substantially heat conductively isolated from one another, and a temperature of the cooling medium in the central passage is controlled to be higher than a temperature of the cooling medium in the circumferential passage; and    supplying heat conductive gases to the spaces between the specimen rear surface and a upper surface of the specimen table, wherein a pressure of the heat conductive gas at the central part space is controlled to be higher than a pressure of the heat conductive gas at the circumferential part space, wherein the ring-like protrusion, the specimen rear surface and the upper surface of the specimen table cooperate to isolate the central part space from the circumferential part space which have different pressures, whereby a temperature profile of the specimen is maintained to be higher in a central portion of the specimen than in a circumferential portion of the specimen during the processing of the specimen.    
   
   
       2 . A plasma processing method according to  claim 1 , wherein a member for substantially suppressing heat conduction is disposed between the central passage and the circumferential passage of the heat conductive member.  
   
   
       3 . A plasma processing method according to  claim 1 , wherein the specimen table further comprises a heat conduction restraining portion disposed between the central portion and the circumferential portion of the heat conductive member.  
   
   
       4 . A plasma processing method according to  claim 1 , wherein the specimen table further comprises a heat conduction restraining portion disposed in the heat conductive member and between the central passage and the circumferential passage of the heat conductive member.  
   
   
       5 . A plasma processing method comprising the steps of locating a specimen on a specimen table having a heat conductive member and provided inside of a processing chamber; supplying a processing gas during evacuation of the inside the processing chamber from a lower portion thereof; and generating plasma inside of the processing chamber so as to process the specimen; wherein the specimen table comprises a ring-like protrusion disposed on an upper surface of the specimen table and at a position between a central portion and a circumferential portion of the specimen table, the ring-like protrusion contacting a rear surface of the specimen and delimiting a central part space and a circumferential part spaces between the upper surface of the specimen table and the rear surface of the specimen, the space being independent of one another; 
 the method further comprising the steps of:    adjusting a temperature of a central portion of the heat conductive member of the specimen table to be higher than a temperature of the circumferential portion of the heat conductive member; and    supplying heat conductive gases to the spaces between the specimen rear surface and the upper surface of the specimen table, wherein a pressure of the heat conductive gas at the central part space is controlled to be higher than a pressure of the heat conductive gas at the circumferential part space, whereby a temperature profile of the specimen is maintained to be higher in a central portion of the specimen than in a circumferential portion of the specimen during the processing of the specimen.    
   
   
       6 . A plasma processing method according to  claim 5 , wherein the specimen table further comprises a heat conduction restraining portion disposed between the central portion and the circumferential portion of the heat conductive member.  
   
   
       7 . A plasma processing method according to  claim 5 , wherein the specimen table further comprises a heat conduction restraining portion disposed in the heat conductive member and between a central passage in the central portion of the specimen table which is supplied with a cooling medium and a circumferential passage in the circumferential portion of the specimen table which is supplied with a cooling medium.