How to limit the deformation to contact surface

Hi Comsol,
I am doing a mechanical deformation simulation. My structure is mainly composed of two parts. The top part is made of glass. The bottom part is made of rubber with Young's modulus of 1.5MPa. There are thee saw tooth structure at the contact surface.
I want to study how does the saw tooth structure deform with certain applied load. I run solid mechanics simulation with boundary load applied on box 2 and fixed constraint applied on box1.

I expect the bottom saw tooth structure make contact with the top glass structure but it didn't. IT GO BEYOND THE CONTACT SURFACE (see Deformation.tif). My question is, how can I limit the saw tooth structure to make contact with the glass, as what should happen in real world, instead of go beyond the physical limit? The attached photo shows the deformation plot.

Thanks!