Method of manufacturing semiconductor devices using light ion implantation and semiconductor device
A first doped region is formed in a single crystalline semiconductor substrate. Light ions are implanted through a process surface into the semiconductor substrate to generate crystal lattice vacancies between the first doped region and the process surface, wherein a main beam axis of an implant beam used for implanting the light ions deviates by at most 1.5 degree from a main crystal direction along which channeling of the light ions occurs. A second doped region with a conductivity type opposite to the first doped region is formed based on the crystal lattice vacancies and hydrogen atoms.
1. A method of manufacturing a semiconductor device, the method comprising:
forming a first doped region in a single crystalline semiconductor substrate;
implanting light ions through a process surface into the semiconductor substrate to generate crystal lattice vacancies between the first doped region and the process surface, wherein a main beam axis of an implant beam used for implanting the light ions deviates by at most 1.5 degree from a main crystal direction along which channeling of the light ions occurs; and
forming a second doped region with a conductivity type opposite to the first doped region based on the crystal lattice vacancies and hydrogen atoms.
2. The method of claim 1 , wherein
an incidence angle variability of the implant beam is at most ±0.5 degree for at least 80% of the process surface.
3. The method of claim 2 , wherein:
the semiconductor substrate has a diamond cubic crystal lattice;
the process surface deviates from a {100} crystal face by at most ±2 degree; and
the main crystal direction is the <100> direction.
4. The method of claim 1 , wherein
an oxygen concentration in the semiconductor substrate is at least 1E15 cm −3 and/or a carbon concentration in the semiconductor substrate is at least 1E13 cm −3 .
5. The method of claim 1 , further comprising:
forming insulated gate field effect transistor cells between a front surface opposite to the process surface and the second doped region, wherein portions of the first doped region form body zones of the transistor cells and the transistor cells are configured to control a current flow through the semiconductor substrate between the front surface and the process surface.
6. The method of claim 1 , wherein:
the light ions are implanted in two or more implants at different acceleration energies; and
a dose of the two or more implants decreases with increasing acceleration energy.
7. The method of claim 1 , further comprising:
implanting light ions at an implant angle between the main beam axis and the main crystal direction greater 1.5 degree.
8. The method of claim 7 , wherein
the implant angle is at least 3.5 degree.
9. The method of claim 8 , wherein
an acceleration energy of any implant implanting the light ions at a deviation of the main beam axis from the main crystal direction by at least 3.5 degree is lower than an implant energy of at least one implant implanting the light ions at a deviation of the main beam axis from the main crystal direction by at most 1.5 degree.
10. The method of claim 1 , wherein
the semiconductor substrate is a silicon substrate and the first doped region is p doped.
11. The method of claim 10 , wherein
before forming the first and second doped regions, an initial net dopant concentration in the semiconductor substrate is lower than 1E14 cm −3 .
12. The method of claim 1 , further comprising:
measuring an initial net dopant concentration in the semiconductor substrate before forming the first and second doped regions; and
determining implantation parameters of at least one implant with the main beam axis deviating from the main crystal direction by at most 1.5 degree so as to compensate for a deviation of the initial net dopant concentration from a target value in at least a section of the semiconductor substrate.
13. The method of claim 1 , further comprising:
adjusting a base doping of the semiconductor substrate by tempering, after the channeled implant of light ions, the semiconductor substrate at a temperature above a formation temperature of oxygen thermal donors.
14. The method of claim 1 , further comprising:
forming, before implanting light ions, an implant mask covering first portions of the semiconductor substrate and exposing second portions of the semiconductor substrate.
15. The method of claim 14 , wherein
the implant mask shadows the first portions against the light ions.
16. The method of claim 14 , wherein
the implant mask scatters the light ions off from the main beam axis.
17. A method of manufacturing a semiconductor device, the method comprising:
forming a p doped region in a single crystalline silicon substrate;
implanting light ions through a process surface into the semiconductor substrate to generate crystal lattice vacancies between the p doped region and the process surface, wherein a main beam axis of an implant beam used for implanting the light ions deviates by at most 1.5 degree from a main crystal direction, along which channeling of the implant light ions occurs; and
forming an n doped region by generating hydrogen-related donors at the crystal lattice vacancies.