Understanding AFM Imaging: Protrusions and Troughs

[garyd]

Hi all
I was wondering if someone could have a look at my answer attempts. I am having great trouble with Q.3 so any help would be greatly appreciated.

Figures are attached

Homework Statement

Q1. Sketch expected image profile for rectangular protrusion from an otherwise locally flat surface if the surface is being imaged with an atomic force microscope with a tip end radius of 50nm and vertical sides. (figure 1)

(i) What will the imaged height of the protrusion be?
(ii)What will the imaged width of the protrusion be?
(iii)Calculate % imaged protrusion broadened compared to original

Q2. Sketch profile from rectangular trough (figure 2)

(i) What will the imaged depth of the trough be?
(ii)What will be the imaged width of the trough be?
(iii)Calculate % imaged protrusion narrowed compared to original

Q3.Sketch profile from rectangular trough (figure 3). AFM tip has an end radius of 40nm and an opening angle of 300 to the vertical

 

[BvU]

No expert. PF doesn't like template being ignored. Never mind in this case. Studied up on your item by looking at googling AFM.
I hope 1 and 2 are ok, they look reasonable to me. Understand r 50 nm horizontally somewhat. Don't fully understand why vertically also r 50 nm.

In 3 I suppose angle 300 means angle 30 degrees ? So tip is equilateral triangle with rounded tip ? And the thing is operated in non-contact mode with a distance of 40 nm between tip and object as in fig 1? In that case it won't go in all that far and image a triangle 220 wide and deep, right ?