Clean room assignment engineering practice Lab Report

Clean room assignment engineering practice - Lab Report Example The next step in the fabrication process is to create the buried channels by implanting phosphorous ions in areas that will eventually be covered by polysilicon gate electrodes. The n-type semiconductor formed by phosphorus contains negatively charged electrons as the primary charge carriers and forms a pn-type diode structure, which serves to localize potential wells deep beneath the silicon/silicon dioxide interface. The potential well illustrated in the central portion of Figure 1 is a schematic drawing of the diode structure. The primary function of the buried channel is to localize integrated electrons away from the silicon/silicon dioxide interface, where they can become trapped during charge transfer. By localizing charge deep within the p-type silicon substrate, transfer of charge occurs more efficiently with a minimum of residual charge remaining in the gate. After the buried channels are formed within the silicon substrate, a layer of silicon dioxide is thermally grown on the silicon wafer surface to provide an insulating base for the gate electrodes. Next, a phosphorous-doped layer of polycrystalline silicon (polysilicon) about 5,000 angstroms thick is grown on top of the oxide layer. This layer of polysilicon comprises the gate electrodes (see Figure 1) and is transparent to visible light, making it an ideal substance for use in CCDs. Although, the fabrication of a complete CCD takes additional steps, the basics of the MOS capacitor assembly have been completed at this point." I Vs V Characteristics (According to M.Aceves, O.Malik, V. Grimalsky V.5 No. 2 (2004) P. 236-237), National Institute for Astrophysics, Optics and Electronics ( INAOE), Electronics Department.) The dynamic I-V characteristics of these MOS structures when linear voltage sweep (60 v/ sec) was applied to the metallic semitransparent gate is shown in the diagrams below. Dynamic I-V Characteristics of fabricated MOS capacitor with silicon dioxide as insulator with positive (above) and negative (below) charge recorded when a triangular sweep voltage ( 60 v/s) was applied to the gate. References Process specialities Inc Davidson Michael - National High Magnetic Field Laboratory,1800 East Paul Dirac Dr, The Florida State University, Tallahassee, Florida, 32310 Aceves, Malik, Grimalsky - National Institute for Astrophysics, Optics and Electronics ( INAOE), Electronics Department, P.O 51 AND 216, Puebla, Pue, Mexico. Physics and

Healthcare Law & Ethics - Advanced Directives Essay

Healthcare Law & Ethics - Advanced Directives - Essay Example Firstly, the will should be made by someone in his sound state of mind. Secondly, a living will should be specific about the duties or decisions to be made. Thirdly, a living will should be voluntary. This means that the maker of a living will should not be under duress to do so. 2. A health care proxy is a written document that permits a patient to appoint someone called an agent to make specific decisions affecting the health of such patient in the event the patient is incapable of making decisions. However, so long as the patient is in position to make decisions himself, the health care proxy will not be effective. Health care proxy should meet certain conditions. In most cases, people appointed as health care proxies are people who are closely related to the patient such as next of kin. Another condition of a health care proxy is that it can not be signed by the physician attending to the patient. In addition, the patient can issue other instructions to nullify the preexisting conditions. The common health care proxies are issued when someone is about to undergo a major medical operation. 3. Durable power of Attorney refers to general, specific as well as health care instructions or powers given to someone that will be exercised when the issuer becomes mentally incompetent. Someone can also sign a durable power of attorney form. Fundamentally, they are not different from other powers of the attorney. However, a few texts or words are added to make them durable. However, just like other powers of the attorney, they only become effective only when the issuer becomes mentally incompetent or incapacitated. Such powers may require the appointed agent to make decisions concerning matters such as how to handle bank transactions, purchasing life insurance, settling claims, buying and selling of property, management of real estates, among others. Such instruction should be make by someone in his