Resistor-Capacitor induced high frequency ghost vibration in Simulink Output

I have performed the numerical simulation of the switching circuit (L - R - C) using Simulink

However, as can be seen below first figure, there are some high frequency ghost vibration in i_s.

Below second figure is the enlarged view at around t_3 where ghost vibration is observed.

I guess this ghost vibration is caused by R-C relations. In here, R is switch resistance; C is parasitic capacitance in diode.

However, if my understanding is right, these phenomenon should not be a vibration but a curve shape.

Therefore, i`m not entirely sure why this ghost vibration occurs.

Please answer on this issue

Best Regard