The temperature of a substrate, while the covering is drawing on it’s surface, страница 36

N_i=I-I_e/e                                    (10.8)

4)  We determine the dispersion coefficient of the chosen material, using the experimental data resulted in section 5.

5)  Now, it is necessary to determine quantity of atoms sputtered from unit of a cathode - target surface in unit of time on the basis of received quantity of ions of working gas, bombarding a surface and determined factor of dispersion of a material of a cathode - target

N_a=N_i·Y(P),                                                 (10.9)

where N_i - quantity of ions of  working gas bombarding a surface;

Y(P) – the dispersion coefficient of a cathode - target.

6)  Further we determine quantity of atoms coming on a substrate surface, using received values of quantity of atoms, sputtered from a surface of a cathode - target.

N=N_a·α,                                              (10.10)

where N_a - quantity of atoms, sputtered from a surface of a cathode - target;

α – the  accommodation coefficient.

7)  Further we determine the distribution function of atoms of a material on a substrate surface. Determination of the distribution function of atoms of a material on a substrate surface is resulted in section 9.

8) Last stage is definition of heat flow distribution on a substrate surface. For this purpose the received distribution function of atoms of a material on a substrate surface and the experimental data on average energy of atoms of various metals in planar and cylindrical MSS (energy in planar magnetron is usually on 5-20 % less, than energy in cylindrical magnetron), resulted in tab. 10.1 [48] is used.

Table 10.1

Average energy, eV, at dispersion of various metals in planar and cylindrical MSS

11 Development of the software for calculation of a heat mode of a substrate when drawing in magnetron sputtering systems

11.1 Algorithm of carrying out of calculations of parameters

In the previous sections of work characteristics of technological process of generation of a covering with help of MSS have been determined. Influence of various parameters on processes of ionization of working gas, dispersion of a material of a cathode - target and sedimentation of a covering is estimated. Last stage of the work to create the algorithm of carrying out of calculations, and also create the software (SW) for definition of a thermal mode of a substrate when drawing coverings with the help of magnetron sputtering systems.

The flow block of algorithm of definition of a substrate heat mode when drawing coverings in MSS is submitted in figure 11.1. We shall consider sequence of calculations. It is quite reasonable to divide the problem of the automated system into three parts:

1) Assigning of initial parameters;

2) Calculation of a heat mode of a substrate;

3) Saving of the designed characteristics.

At the first stage the user sets the initial data necessary for carrying out calculations. Those are the following parameters: