 Silicon is a key component of the semiconductor industry and is the precursor to many semiconductor devices. Single-crystal silicon can be produced through the Zhikrowski method, from which silicon wafers can be cut and polished. This experiment will investigate how particle size of crushed single-crystal silicon will influence the diffraction pattern of XRD characterization. This will be done by crushing and separating silicon powder using sieves of different sizes. First, a single-crystal sample is prepared for XRD by breaking a silicon wafer. Silicon wafers typically have cut edges called flats to provide information about the wafer, such as its crystal orientation and if it's an n-type or p-type semiconductor. The single-crystal silicon can be easily cleaved by inducing a defect on its surface with a hard object, such as this tungsten carbide glass cutter. Using a special tool to provide bending stress, the silicon wafer fractures along its preferred crystallographic direction. Based on how this wafer fractures, you should be able to guess the crystal orientation of this wafer and predict which diffraction peaks it will exhibit. The sample is further reduced in size to fit the XRD sample holder. The silicon sample is adhered onto the sample holder using double-sided tape. The remaining silicon is broken into smaller pieces, which will be used to make powder samples of different sizes. The large pieces of silicon are crushed using a mortar and pestle. A mask should be worn while crushing silicon to prevent inhalation of silicon dust. The silicon powder is ready to be separated using three sieves with mesh sizes of 150 micrometers, 90 micrometers, and 45 micrometers. The mesh size refers to the opening created by the wire mesh. The silicon powder is added to the top sieve with largest mesh size and is shook back and forth. After some time, silicon powder will accumulate in different levels pertaining to their particle size. The silicon crystals above 150 microns are crushed again to reduce their size and obtain more powder. Samples can be collected after sufficient separation. Crystals above 150 microns are too coarse to stay in the XRD holder and are discarded. The first powder sample are particles between 90 and 150 microns. The second powder sample are particles between 45 and 90 microns. The final powder sample are particles smaller than 45 microns. These samples will be put into the sample holder for XRD. First, the single crystal sample is measured using XRD. While the single crystal sample is being measured, a powder sample is prepared in its holder. Powder is carefully placed in the middle of the sample holder and spread around. A glass slide is used to make sure the sample is flush with the surface of the sample holder. This powder sample is ready to be placed into the XRD and measured. The process is repeated for other powders of different sizes. These are the normalized results from XRD. You will be given the data to graph and analyze. Although all four samples are of the same material, they produce very different XRD patterns. Notice how the relative intensity of different peaks changes between the different samples. Students should think about what causes this and why preparation of fine particles is important for powder XRD. A closer look at the main diffraction peak of the single crystal silicon wafer reveals that it is actually two peaks. And a smaller peak is also apparent. What explanation can be given for the appearance of these extra peaks? Lastly, the silicon powder is disposed of into a labeled waste container.