Method for pretreating semiconductor substrate by photochemically removing native oxide

A method for pretreating a silicon semiconductor substrate in order to remove a natural oxide film or contaminant adhering on a surface of the semiconductor substrate, said method comprising the steps of:

• placing said silicon semiconductor substrate in a chamber;
• introducing into said chamber a reaction gas capable of reacting with said natural oxide film or contaminant, said reaction gas comprising HCl;
• heating the semiconductor substrate at a temperature in the range of 200.degree.-700.degree. C. by irradiating said semiconductor substrate with light;
• and
• irradiating the reaction gas introduced into said chamber with light at said temperature in the range of 200.degree.-700.degree. C., while said semiconductor substrate is heated,
• said light having a wavelength which causes a photochemical reaction of the natural oxide film or contaminant adhering on said semiconductor substrate surface with said reaction gas.

A method for pretreating a silicon semiconductor substrate in order to remove a natural oxide film or contaminant adhering on a surface of the silicon semiconductor substrate, said method comprising the steps of:

• placing said silicon semiconductor substrate in a chamber;
• introducing HCl gas into the chamber;
• heating said silicon semiconductor substrate at a temperature in the range of 200.degree.-700.degree. C., and
• irradiating said HCl gas with an excimer laser which is introduced into said chamber along a path parallel with the surface of said silicon semiconductor substrate.

A method for pretreating silicon semiconductor substrates in order to remove a natural oxide film or contaminant adhering on the surface of the silicon semiconductor substrates, said method comprising the steps of:

• placing into a chamber a rotating susceptor capable of holding a plurality of the silicon semiconductor substrates;
• mounting the plurality of the silicon semiconductor substrates on the rotating susceptor such that the back side of each silicon semiconductor substrate contacts the surface of the rotating susceptor;
• introducing HCl gas into the chamber;
• rotating the rotating susceptor with the plurality of the silicon semiconductor substrates;
• and
• irradiating each silicon semiconductor substrate with infrared rays and irradiating the HCl gas with ultraviolet rays.