Method of doping impurities, and electronic element using the same
View Patent ↗The invention provides a method of doping impurities that includes a step of doping impurities in a solid base substance by using a plasma doping method, a step of forming a light antireflection layer that functions to reduce light reflection on the surface of the solid base substance, and a step of performing annealing by light radiation. According to the method, it is possible to reduce the reflectance of light radiated during annealing, to efficiently apply energy an impurity doped layer, to improve activation efficiency, to prevent diffusion, and to reduce sheet resistance of the impurity doped layer.
1. A method of doping impurities, comprising the steps of:
measuring optical characteristics and thickness of the impurity doped region;
selecting a light antireflection layer on the basis of the measured optical characteristics and thickness;
doping impurities in a solid base substance by using a plasma doping method so as to form an impurity doped region;
forming a light antireflection layer, which functions to reduce light reflection, on a surface of the solid base substance; and
performing annealing by light radiation.
2. The method of doping impurities according to claim 1 , wherein the light antireflection layer is selected in the step of selecting so that the absorption of the light used in the step of performing annealing into the impurity doped region is maximum.
3. The method of doping impurities according to claim 1 , further comprising the step of:
changing the surface of the solid base substance into amorphous structure by using plasma, before the step of doping impurities.
4. The method of doping impurities according to claim 1 , wherein the optical characteristics include any one of a refraction index, extinction coefficient, absorption coefficient, reflectance, transmittance, and absorption rate.
5. The method of doping impurities according to claim 1 , wherein the solid base substance is a crystal silicon substrate.
6. The method of doping impurities according to claim 1 , wherein the light antireflection layer is a transparent layer that has a refraction index lower than that of the impurity doped region.
7. The method of doping impurities according to claim 1 , wherein the light antireflection layer is a dielectric multilayer.
8. The method of doping impurities according to claim 1 , wherein light having a wavelength of 500 nm or more is used in the step of performing annealing.
9. The method of doping impurities according to claim 1 , further comprising the step of:
feeding back the measurement results obtained in the step of measuring to the thickness of the light antireflection layer.
10. The method of doping impurities according to claim 1 , further comprising the step of:
feeding back the measurement results obtained in the step of measuring to a plasma doping step.