Method of processing a semiconductor substrate by thermal activation of light elements

Method of processing a substrate containing at least one semiconductor of the SiXAY type, x being a strictly positive number, y being a positive number and A designating a chemical element or a compound of several chemical elements of the fourteenth column of the periodic table of elements, and comprising at least four separate types of light elements, the method comprising at least the following steps:

• carrying out a first anneal of the substrate at a temperature T1, corresponding to a thermal activation temperature for a first one of the four types of light elements,
• carrying out, after the first anneal, a second anneal of the substrate at a temperature T2, corresponding to a thermal activation temperature for a second one of the four types of light elements,
• carrying out, after the second anneal, a third anneal of the substrate at a temperature T3, corresponding to a thermal activation temperature for a third one of the four types of light elements,
• carrying out, after the third anneal, a fourth anneal of the substrate at a temperature T4, corresponding to a thermal activation temperature for a fourth one of the four types of light elements,
• each anneal comprising a holding at the temperature T1, T2, T3 or T4 for a predetermined time period, and the temperatures T1, T2, T3 and T4 being such that T1>T2>T3>T4.