irfpy.util.sputtering

A formulation of sputtering

Code author: Yoshifumi Futaana

ThompsonSigmund(n0, y, ene_bind, ene_in, m1, m2)

Thompson-Sigmund energy spectrum.

class irfpy.util.sputtering.ThompsonSigmund(n0, y, ene_bind, ene_in, m1, m2)

Bases: object

Thompson-Sigmund energy spectrum.

>>> ts0 = ThompsonSigmund(1, 0.5, 1.5, 1000., 1, 25)
>>> print('%.3f' % ts0.ei)
147.929

Todo

Clarify the unit system. Energy looks eV. What about the energy spectrum?

Initialize the formulation.

$$F(E)=nC\frac{E}{(E+E_b{)}^3}(1-\sqrt{\frac{E+E_b}{E{i}^{\prime }}})$$

Note that C is a parameter including the yield. The unit of C is the energy. After several argebla, C is obtained from yield, Y, like

$$C=\frac{Y}{\frac{1}{2E_b}-\frac{4}{3\sqrt{EbE{i}^{\prime }}}}$$

Parameters:

• n0 – Density.

• y – Yeild.

• ene_bind – Binding energy, $E_b$

• ene_in – Impinging beam energy, $E_i$

• m1 – Mass of impinging beam. Unitless.

• m2 – Mass of target. Unitless.

f(e)

Return the energy distribution at certain e.

irfpy.util.sputtering.doctests()