1 MFA1M Lab 1 Report: A Practical Study On Leica Optical Microscopic System Lars Karlot Stubberud Bratrud, Haakon Karlsen and Bao Ho Dang Abstract—In this lab work, extensive functionalities of Leica optical microscopy system is investigated, using a set of RF MEMS Switch samples. The practical work focused mainly on viewing, capturing and measuring dimensions of the switches at various magnification level, with the aid of Leica Application Suite software system. Dark field microscopy was also reviewed in this paper. Index Terms—Microscopy, Numeric aperture, Depth of focus, Depth of field, Dark field microscopy I. I NTRODUCTION O PTICAL microscope, invented in late 1500s, is an optical device that helps extend the ability of human eyes when viewing microscopic objects, things whose size smaller than the resoltion of eyes. Soon after its appearance, optical micro- scopes were intensively used in various fields of science and technology like biology, chemistry, medicine and afterwards, microelectronic, MEMS. In this project, the optical microscopy system to be used is Leica system, including Leica microscope and Leica ap- plication suite (LAS) software. The case study, a set of RF MEMS Switches, is investigated and measured using the LAS software. In the next section we will describe the scientific material and method in optical microscopy. After that, the practical re- sults of the lab work is presented, following by our discussion on these result. II. MATERIAL AND METHOD A. Equipments Our equipments include a wafer with RF switch test pattern, Leica DM 4000 M with camera attachment and computer with Leica Application Suite installed. B. Formulas Relationship between Depth of focus and numerical apertureNA: D f ocus =1.12 λM 2 (NA) 2 r n 2 - ( NA M ) 2 (1) , where n is the refractive index of the environment between the lens and image plane. Relationship between resolution s and NA s = 0.61λ NA (2) C. Method Part 1: Getting started. The first part of the lab was to basically get acquainted with the microscope. It was stressed that we should be able to see clearly through both oculars as this gives us somewhat of a depth perception making us able to distinguish details better. To do this, first we set the objective with least magnification (2.5x) in position and tried to see through the eyepiece. The recommended procedure for this is as follows. 1. With right eye, look through the right eyepiece and bring the specimen into sharp focus. 2. Then, with left eye, view the same specimen and rotate the left eyepiece tube until the object is brought into sharp focus. Do not use the focus dial. We also experienced that it was necessary to adjust the length between the eyepiece tubes to get a correct image. The next step was to set the beam splitter to 50/50, that is, half the intensity of the light goes to the eyepieces and the other half to the camera attachment. This is very helpful for when acquiring an image on the computer, as the software experiences a 1-2 second lag which makes it frustrating to do initial adjustmen of the focus. It is important to know that there are a difference in the focus between the image the camera sees and what we see in the eyepiece. We now had the possibility to acquire images from the camera and do non-live analysis through the ”Analysis” tab of the software; like measuring dimensions, angles, etc. Part 2: Measuring. In the next part we did different measurements of the test specimen. The specimen was a test pattern of RF switches consisting of bridges of different lengths (indicated next to each bridge, 150 to 750 μm) over transmission lines. The bridges and transmission lines are made of gold and the transmission line center conductor is covered with an isolating layer of Silicon-Nitride which has a blue color. 1. Length and width of all the bridges. 2. Length and width of the center transmission line. 3. Angle of the metal-edge at the ancors. 4. Height-distance from top on bridge to top of the nitride layer. 5. Height-distance from top on bridge to top of the ground conductor. For the length and width measurements we used the objective with 2.5x magnification. To set the measurement tool as precise as possible we used the Shift button on the keyboard to bring up a magnification of the area around our mouse pointer. The measurements were