Method of processing target object

Abstract

A method of processing a target object is provided. The target object includes a first protrusion portion, a second protrusion portion, and a groove portion provided on a main surface of the target object and defined by the first protrusion portion and the second protrusion portion and an inner surface of the groove portion is included in the main surface of the target object. The method comprises forming a protection film conformally on the main surface of the target object after the forming of the protection film conformally, repeatedly performing a plasma etching on a bottom portion of the groove portion of the target object and performing the forming of the protection film and the performing of the plasma etching N times (N is an integer equal to or larger than 2). The protection film is formed depending on a shape of the groove portion which has been changed by the plasma etching.

We claim: 
     
         1 . A method of processing a target object, the method comprising:
 providing the target object including a first protrusion portion, a second protrusion portion, and a groove portion, the groove portion being provided on a main surface of the target object and defined by the first protrusion portion and the second protrusion portion and an inner surface of the groove portion being included in the main surface of the target object;   forming a protection film conformally on the main surface of the target object;   performing a plasma etching on a bottom portion of the groove portion of the target object after the forming of the protection film conformally; and   repeatedly performing the forming of the protection film and the performing of the plasma etching N times (N is an integer equal to or larger than 2),   wherein the protection film is formed depending on a shape of the groove portion which has been changed by the plasma etching.   
     
     
         2 . The method of  claim 1 ,
 wherein a position at which the protection film is formed is adjusted depending on a depth of the groove portion which has been increased by the plasma etching.   
     
     
         3 . The method of  claim 1 ,
 wherein, in the forming of the protection film conformally, the protection film is conformally formed on the main surface of the target object by repeatedly performing a sequence comprising;   supplying a first gas into a processing vessel of a plasma processing apparatus in which the target object is accommodated;   purging a space within the processing vessel after the supplying of the first gas is performed;   generating plasma of a second gas within the processing vessel after the purging of the space is performed; and   purging the space within the processing vessel after the generating of the plasma of the second gas is performed,   wherein, in the supplying of the first gas, plasma of the first gas is not generated.   
     
     
         4 . The method of  claim 1 ,
 wherein, in the forming of the protection film conformally, the protection film is conformally formed on the main surface of the target object by supplying a first gas into a processing vessel of a plasma processing apparatus in which the target object is accommodated and purging a space within the processing vessel after the supplying of the first gas is performed,   in the plasma etching of the bottom portion of the groove portion, the bottom portion of the groove portion of the target object is etched with plasma of an oxygen-containing gas, and   in the supplying of the first gas, plasma of the first gas is not generated.   
     
     
         5 . The method of  claim 1 ,
 wherein the repeatedly performing includes a first processing and is performed M times (M is an integer equal to or lager than 1 and equal to or smaller than N−1), and the repeatedly performing includes a second processing and is performed N−M times,   wherein the first processing is included in the forming of the protection film conformally,   in the first processing, the protection film is conformally formed on the main surface of the target object by repeatedly performing a sequence comprising:   supplying a first gas into a processing vessel of a plasma processing apparatus in which the target object is accommodated;   purging a space within the processing vessel after the supplying of the first gas is performed;   generating plasma of a second gas within the processing vessel after the purging of the space is performed; and   purging the space within the processing vessel after the generating of the plasma of the second gas is performed,   wherein the second processing is included in the forming of the protection film conformally,   in the second processing, the protection film is conformally formed on the main surface of the target object by supplying the first gas into the processing vessel and purging the space within the processing vessel after the supplying of the first gas is performed,   in the plasma etching of the bottom portion of the groove portion following the second processing, the bottom portion of the groove portion of the target object is etched by plasma of an oxygen-containing gas, and   plasma of the first gas is not generated in the supplying of the first gas performed in the first processing and the supplying of the first gas performed in the second processing.   
     
     
         6 . The method of  claim 3 ,
 wherein the second gas contains oxygen atoms.   
     
     
         7 . The method of  claim 6 ,
 wherein the second gas contains a carbon dioxide gas or an oxygen gas.   
     
     
         8 . The method of  claim 3 ,
 wherein the first gas contains an aminosilane-based gas.   
     
     
         9 . The method of  claim 8 ,
 wherein the first gas contains monoaminosilane.   
     
     
         10 . The method of  claim 8 ,
 wherein the aminosilane-based gas contained in the first gas includes aminosilane having one to three silicon atoms.   
     
     
         11 . The method of  claim 8 ,
 wherein the aminosilane-based gas contained in the first gas includes aminosilane having one to three amino groups.   
     
     
         12 . The method of  claim 1 ,
 wherein a film thickness of the protection film formed in the forming of the protection film conformally is equal to or larger than 2 nm and equal to or smaller than 8 nm before the plasma etching of the bottom portion of the groove portion is performed.   
     
     
         13 . The method of  claim 1 ,
 wherein a mask is formed on a region belonging to the first protrusion portion while the mask is not formed on a region belonging to the second protrusion portion,   a deposition film is formed on the mask, and   the protection film is not formed on the deposition film.   
     
     
         14 . The method of  claim 1 ,
 wherein a height of a region belonging to the first protrusion portion is greater than a height of a region belonging to the second protrusion portion.   
     
     
         15 . The method of  claim 1 ,
 wherein the main surface includes an upper surface of a region belonging to the second protrusion portion and a side surface of the groove portion,   after the plasma etching of the bottom portion of the groove portion, a protection film formed on the upper surface of the region belonging to the second protrusion portion is removed while a protection film formed on the side surface of the groove portion remains.   
     
     
         16 . The method of  claim 1 ,
 wherein the forming of the protection film and the plasma etching of the bottom portion are performed in a single processing vessel.   
     
     
         17 . A method of processing a target object, the method comprising:
 providing the target object including a protrusion portion and a groove portion, the groove portion being provided on a main surface of the target object and defined by the protrusion portion and an inner surface of the groove portion being included in the main surface of the target object;   forming a protection film conformally on the main surface of the target object;   performing a plasma etching on a bottom portion of the groove portion of the target object after the forming of the protection film conformally; and   repeatedly performing the forming of the protection film and the performing of the plasma etching N times (N is an integer equal to or larger than 2),   wherein the protection film is formed depending on a shape of the groove portion which has been changed by the plasma etching.