Zero drop force

I would like to have RigidBody2D squares falling down on top of each other, but apply zero force when they land. The problem is that when they land on each other, they bounce a little and move around. I don't want that, I want zero bounce. I tried messing with mass, (I make it small when it's falling and increase it when it's landed), some of the settings in the Project Settings, and also Physics Materials. I need the physics of an actual object so I would like to keep gravity and I can't freeze their positions. Any advice?

Each game object has a rigidbody2d and a collider component.