Surface treatment apparatus and surface treatment method

Abstract

HF-originated radicals generated in a plasma-forming chamber are fed to a treatment chamber via feed holes, while HF gas molecules as the treatment gas are supplied to the treatment chamber from near the radical feed holes to suppress the excitation energy, thereby increasing the selectivity to Si to remove a native oxide film. Even with the dry-treatment, the surface treatment provides good surface flatness equivalent to that obtained by the wet-cleaning which requires high-temperature treatment, and further attains growth of Si single crystal film on the substrate after the surface treatment. The surface of formed Si single crystal film has small quantity of impurities of oxygen, carbon, and the like. After sputtering Hf and the like onto the surface of the grown Si single crystal film, oxidation and nitrification are applied thereto to form a dielectric insulation film such as HfO thereon, thus forming a metal electrode film. All through the above steps, the substrate is not exposed to atmospheric air, thereby suppressing the adsorption of impurities onto the interface, and thus obtaining a C-V curve with small hysteresis. As a result, good device characteristics are obtained in MOS-FET.

1 .- 22 . (canceled) 
     
     
         23 . A method of treating a surface of semiconductor substrate placed in a treatment chamber, comprising the steps of:
 generating plasma by exciting a plasma-forming gas containing HF in a plasma-forming chamber;   selectively feeding a radical in the plasma from the plasma-forming chamber to the treatment chamber;   feeding a treatment gas containing unexcited HF into the treatment chamber; and   treating the surface of the semiconductor substrate by an atmosphere of a mixture of the radical and the treatment gas, fed into the treatment chamber.   
     
     
         24 . A method of  claim 23 , wherein the treatment of gas contains at least HF by a fraction from 0.2 to 1.0 to the total amount of the treatment gas, and preferably the treatment gas is composed of substantially HF. 
     
     
         25 . A method of  claim 23 , wherein the plasma-forming gas is composed of substantially HF. 
     
     
         26 . A method of  claim 23 , wherein the selective feeding of the radical to the treatment chamber is conducted by feeding the radical from the plasma chamber to the treatment chamber, allowing the radical to pass through a radical-passing hole formed in a plasma-confinement electrode plate partitioning the plasma chamber from the treatment chamber, while rejecting ions in the plasma. 
     
     
         27 . A method of  claim 23 , wherein the semiconductor substrate is a Si substrate, and the cleaning treatment of the Si substrate is conducted after removing native oxide film on the Si substrate by etching. 
     
     
         28 . A method of forming a gate insulation film of MOS structure, comprising the steps of:
 cleaning the surface of a Si substrate by the method of  claim 27 ;   transferring the surface-cleaned Si substrate to an expitaxial chamber without exposing the Si substrate to atmospheric air, and forming an expitaxial layer on the surface-cleaned Si substrate;   transferring the Si substrate having the expitaxial layer formed thereon to a sputtering chamber without exposing the Si substrate to atmospheric air, and forming a dielectric film on the epitaxial layer by sputtering; and   transferring the Si substrate having the dielectric film formed thereon to an oxidation-nitrification chamber without exposing the Si substrate to atmospheric air, and oxidizing, nitrifying, or oxnitrifying the dielectric film to form the gate insulation film.   
     
     
         29 . A method of  claim 28 , wherein the dielectric film is made of the one selected from the group consisting of Hf, La, Ta, Al, W, Ti, Si and Ge, or an alloy thereof. 
     
     
         30 . An apparatus of treating a semiconductor substrate, including a treatment chamber for treating the surface of the semiconductor substrate, comprising:
 a plasma-forming chamber generating plasma by exciting a plasma-forming gas containing HF;   means for selectively feeding a radical in the plasma from the plasma-forming chamber to the treatment chamber; and   means for feeding a treatment gas containing unexcited HF into the treatment chamber, and   thus treating the surface of the semiconductor substrate by an atmosphere of a mixture of the radical and the treatment gas, fed into the treatment chamber.   
     
     
         31 . An apparatus of treating a semiconductor substrate of  claim 30 , wherein the means for selectively feeding the radical to the treatment chamber is a plasma-confinement electrode plate which partitions the plasma chamber from the treatment chamber, and the plasma-confinement electrode plate has a radical-passing hole formed which connects the plasma chamber with the treatment chamber, thus feeding the radical through the radical-passing hole from the plasma chamber to the treatment chamber, while rejecting ions in the plasma.