Sergei Skorobogatov's student project suggestions


Here are some ideas towards Part Ib and Part II projects in Computer Science. The descriptions provided are only vague ideas, not ready-to-use proposals for a particular type of project.

I will take care after all of the hardware designs necessary for the projects, so unless explicitly requested most of the projects will involve only writing software (either for a PC or a microcontroller).


Joystick control of a motorised stage with displaying current position

Resources:

Details:

For optical observation under a microscope it is easier to move a sample using a motorised stage controlled by a joystick. The movement should be sensitive to the angle of the joystick handle and the speed should be increased if the handle is at the farest position. The LCD should always display the absolute coordinate of the stage (can be requested from the controller). For measurements, relative coordinates can be set and displayed. It is difficult to keep the image always in focus therefore compensation for the Z-coordinate should be provided and automatically adjusted during the X-Y move. The software should have convenient GUI for controlling the motorised stage parameters such as acceleration, speed and travel limits and give access to most of the controller commands.

Current problems:



Laser scanning with a motorised stage

Resources:

Details:

Laser scanning is used in semiconductor failure analysis for various applications from detecting p-n junctions to reading the transistors' state. The project is aimed on buiding a laser scanning system that moves the sample using a motorised stage so that the laser hit all the points on the surface. It is difficult to keep the image always in focus therefore compensation for the Z-coordinate should be provided and automatically adjusted during the X-Y move. The response is acquired with an oscilloscope. Then the data is collected from the oscilloscope and analysed by software. First, the linearity should be restored because the stage does not move linearly in the beginning and the end of the specified travel. Then the result should be presented in suitable graphical form, for example, by using a MatLab.

Current problems:



Merging digital pictures

Resources:

Details:

Once the surface of a chip is photographed it is necessary to combine all the images together into a single database. A user-friendly shell should be used to navigate over this large image with the possibility to zoom in and out, measuring distances between any objects and retracting relative coordinates for any point. The program should be able to manage several planes (for multilayer chips) synchronising them and displaying either one selcted layer or 4 layers (1/4 of a screen) at a time.

Current problems:



Projects listed below cannot be implemented straght away because some hardware issues are not sorted out yet.


Taking a mosaic of pictures of a semiconductor chip

Resources:

Details:

A first step in reverse engineering of semiconductor chips is preparing a high-resolution optical image of its surface. This involves taking digital pictures under a microscope. Because the pictures are usually taken with a high magnification, the amount of pictures very often exceeds one hundred. This is almost impossible to do manually and a computer controlled motorised stage and a digital camera should be used.

Current problems:



Laser scanning mirror interface and control

Resources:

Details:

For real-time laser scanning applications either rotating prizms or voice-coil mirrors are used. This allows one to scan the surface with 2-5 frames/second speed which is enough for laser scanning microscopy. The same idea is used to draw laser pictures onto a wall where the laser is modulated with a video signal.

Current problems:



Sergei Skorobogatov <Sergei.Skorobogatov (at) cl.cam.ac.uk>
created 08-10-2004 -- last modified 09-10-2004 -- http://www.cl.cam.ac.uk/~sps32/