Method of forming a germanium thin film

Abstract

A method of forming a germanium thin film on an underlying film includes forming a germanium seed layer by absorbing a germanium on a surface of the underlying film using an aminogermane-based gas, and forming a germanium thin film on the germanium seed layer using a germane-based gas.

1 . A germanium thin film formation apparatus which forms a germanium thin film on an underlying film, the germanium thin film formation apparatus comprising:
 a process chamber which houses an object to be processed having the underlying film on which the germanium thin film is to be formed;   a process gas supplying mechanism which supplies gas used for a process into the process chamber;   a heating device which heats the object to be processed housed in the process chamber;   an exhauster which evacuates the interior of the process chamber; and   a controller configured to control the process gas supplying mechanism, the heating device, and the exhauster,   wherein the controller controls the process gas supplying mechanism to:   supply a aminogermane-based gas to the process chamber to form a germanium seed layer on an underlying film by absorbing a germanium on the surface of the underlying film; and   supply a germane-based gas to the process chamber to form a germanium thin film on the germanium seed layer; and   wherein the controller controls the heating device to set a process temperature inside the process chamber to a range of 200 to 500 degrees C.   
     
     
         2 . The apparatus of  claim 1 , wherein the surface of the underlying film contains moisture. 
     
     
         3 . The apparatus of  claim 1 , wherein moisture is applied on the surface of the underlying film before forming the germanium seed layer. 
     
     
         4 . The apparatus of  claim 1 , wherein the surface of the underlying film is exposed to a moisture-containing gas before forming the germanium seed layer. 
     
     
         5 . The apparatus of  claim 4 , wherein the moisture-containing gas is atmosphere. 
     
     
         6 . The apparatus of  claim 1 , wherein the surface of the underlying film is washed with water before forming the germanium seed layer. 
     
     
         7 . The apparatus of  claim 2 , wherein the moisture is selected from a hydroxyl group. 
     
     
         8 . The apparatus of  claim 1 , wherein the aminogermane-based gas includes at least one selected from a group consisting of the following gases:
 GeH(NMe 2 ) 3 ,   GeH(NMeEt) 3 ,   GeH(NEt 2 ) 3 ,   GeH(NHEt) 3 ,   GeH(NHi-Pr) 3 ,   GeH(NHt-Bu) 3 ,   GeH 2 (NMe 2 ) 2 ,   GeH 2 (NMeEt) 2 ,   GeH 2 (NEt 2 ) 2 ,   GeH 2 (NHi-Pr) 2 ,   GeH 2 (NHt-Bu) 2 ,   GeH 3 (NMe 2 ),   GeH 3 (NMeEt),   GeH 3 (NEt 2 ),   GeH 3 (NHEt),   GeH 3 (NHi-Pr), and   GeH 3 (NHt-Bu).   
     
     
         9 . The apparatus of  claim 1 , wherein the germane-based gas includes at least one selected from a group consisting of the following gases:
 GeH 4 ,   Ge 2 H 6 ,   GeCl 4 ,   GeHCl 3 ,   GeH 2 Cl 2 , and   GeH 3 Cl.   
     
     
         10 . The apparatus of  claim 1 , wherein the germanium thin film is doped with a dopant containing at least one selected from a group consisting of the following elements:
 Boron (B),   Phosphorus (P),   Arsenic (As),   Oxygen (O),   Carbon (C), and   Nitrogen (N).