Page 1 of 2 - About 17 Essays
  • Importance Of Optical Constants

    title>INTRODUCTION Optical constants (complex refractive index n, complex dielectric function ϵ, and reflection and absorption coefficients R and α) of materials are of great importance for optical metrology in the semiconductor industry.1,2 A high-performance complementary-metal-oxide-semiconductor process flow with 11 layers of metal requires about 75 photolayers and may contain up to 100 thickness measurements, most of them performed using spectroscopic ellipsometry.3 This technique has been described in various books with increasing levels of sophistication.4–7 Since most microelectronic devices are built on a Si wafer, the optical constants of Si and SiO2 are the most important ones and have been determined with greater accuracy than other materials.8 They are often referred to as Woollam silicon and used almost universally for thickness measurements in factories around the world. For many materials, optical constants have been tabulated by Palik9 and Adachi.10 Optical constants of intrinsic materials are related to their vibrational and electronic properties.11–15 Optical constants are determined using different techniques: below16 or near17,18 the band gap of a semiconductor, the absorption coefficient α and refractive index n are determined using transmission and minimum-deviation prism19 measurements, respectively. These techniques (and data resulting from them) are still the most useful today and have not been replaced by more modern methods, such as…

    Words: 1499 - Pages: 6
  • Informative Essay On Germanium

    Ethan Germanium is my superhero’s name. He comes from a good wealthy family that doesn’t understand him . It was 1886 and Ethan’s fifth birthday he and his mother were going to the kitchen to make a cake when robbers broke in. The robbers kidnapped Ethan and his mother.The reason to why he was kidnapped was because of his family’s wealth. His father was supposed to pay a ransom, but he never got the chance to because he was in a meeting and couldn’t answer his phone. The kidnappers decided to…

    Words: 1050 - Pages: 5
  • Disappearing Spoon Chapter Summary

    For example, to clarify the relationship between the nearly physically identical elements Silicon and Germanium, the author used the analogy, “near twins and the black sheep,” singeling out Germanium as the “black sheep” although the pair of elements are “near twins.” Germanium and Silicon are both metalloids used in the technology and machine industries, however Silicon proved to be cheaper and more abundant, so Germanium has decreased drastically in it’s importance. To ensure further…

    Words: 949 - Pages: 4
  • Dmitri Mendeleev: The Creation Of The Periodic Table?

    properties alike. He realized through observations that the atomic weights of the elements increased between each family indicating that more elements existed. Although he made his periodic table before the Russian chemist, Dmitri Mendeleev, he failed to publish it before this man. Dmitri Mendeleev’s table was virtually the same but instead he described that it “could be used to predict not only the atomic weight of missing elements, but also their actual properties” (Chemistry Explained,…

    Words: 1065 - Pages: 5
  • Advantages And Cons Of Technology

    It modifies the electrical properties of substances such as silicon and germanium. Another benefit of boron for our modern technology is its use in neodymium magnets. These powerful magnets are an alloy of neodymium, iron and bron. The magnets used are found in computers, specifically hard drives. E-waste, short for electronic waste, can be any outdated or obsolete appliance or electronic device found in offices, homes and pants pockets. Televisions, microwaves, computers and cellphones are all…

    Words: 1066 - Pages: 5
  • Item 3.2 Graph Research Paper

    therefore have denser atoms. This, combined with their heavier atomic weight, contributes to the transition metals having higher densities than others. There are several anomalies; those being gases (e.g. Oxygen and Argon), which don’t have a density. The melting point of an element depends on the strength (or weakness) of its bonds with another element, be it the same or different. Covalent bonds are especially strong, which is why Carbon has such a high melting point; Carbon…

    Words: 1001 - Pages: 5
  • The Basis Of Mendeleev's Periodic Table

    The basis of Mendeleev’s periodic table was categorizing the elements according to their physical and chemical characteristics with regard to their atomic weights. Mendeleev was the first to come up with a structure for the periodic table with columns and rows. There were other scientists who have worked on tabulating information of the elements even before Mendeleev, however, he was the first scientist to come up with a periodic trend to predict the properties of elements which were not…

    Words: 1046 - Pages: 5
  • Evolution Of Technology

    By far the most interesting advancement in computers to me was the development of the “supercomper” called ATLAS. The University of Manchester developed ATLAS in the United Kingdom and it was officially authorized in 1962. This computer was unlike anything seen before; it was ten times faster then any other computer built. There were many different changes in to the make the supercomputer so much faster and smarter. They changed their transistors from germanium to silicon. At this point they…

    Words: 985 - Pages: 4
  • Essay On Walter Cunningham In To Kill A Mockingbird

    run-of-the-mill people, that you are the product of several generations’ gentle breeding … and that you should try to live up to your name” (Pg.177). Aunt Alexandra’s ideals make it very evident that since the Finch family belonged to the highest social class, Jem and Scout were expected to act accordingly. Rather than climbing trees, going hunting with their air rifles and spending the majority of their time outdoors, Scout and Jem were continuously told to spend their time going to church and…

    Words: 1280 - Pages: 6
  • Essay On The Periodic Table Of Elements

    Law of Octaves but it did not prove to be accurate for any elements heavier than calcium (cK-12 1-2). The creation of the periodic table is credited to Dmitri Mendeleev, a Russian chemist. Mendeleev arranged the periodic table in correspondence with the atomic mass of each element. As shown in figure 1, he arranged the families horizontally and the periods vertically. He found that when he arranged the elements in horizontal rows, leaving blanks for elements he had not discovered, a certain…

    Words: 1141 - Pages: 5
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