Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
2.
J Res Natl Inst Stand Technol ; 99(5): 605-639, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-38327695

RESUMO

To successfully construct semiconductor devices, the semiconductor industry must measure fundamental material parameters, especially when developing new materials; measure the quality of the material as it is grown; accurately determine the details of thin films, quantum wells, and other microstructures that control or affect device performance; and measure properties of the devices themselves. Properties that need to be determined, therefore, include basic band structure and transport parameters, such as energy gap values and carrier scattering times; the presence and concentration of impurities and defects; alloy parameters; layer thicknesses; the distribution of materials in complex structures; and many others. This process of determining a wide range of material, structural, and device parameters is called characterization. The semiconductor industry uses many characterization methods which draw on electrical, chemical, and other approaches. Among these, optical characterization techniques, defined as those using electromagnetic radiation from the ultraviolet to the far infrared, stand out because they arc nondestructive and require minimal sample preparation since no contacts arc needed. These features arc of great importance for production use or to examine finished devices. Another benefit is that, unlike electrical methods which require fixed contacts, optical techniques can give two- or three-dimensional maps of properties over the extent of a semiconductor wafer. The six techniques described in this paper (cllipsometry, infrared spectroscopy, microscopy, modulation spectroscopy, photolumincscence, and Raman scattering) were chosen because they are currently or potentially widely used in the industry; they measure a broad array of semiconductor parameters; and they operate in different regions of the electromagnetic spectrum. The discussion of each technique indicates the basic semiconductor quantities measured, gives the scientific basis of the technique, and indicates how the measurement is made. Illustrative examples from the literature are discussed in detail, showing applications to important semiconductor materials. More information can be obtained from the detailed list of references included.

5.
Appl Opt ; 31(21): 4305-9, 1992 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-20725417

RESUMO

Reflectance of six optical-black coatings was remeasured over the near-infrared to the far-infrared region after nearly 6 years in space aboard the Long Duration Exposure Facility satellite. Measurements were made at room temperature and at cryogenic temperatures. The most notable effect was a general decrease in reflectance for typical samples at all wavelengths. Analysis indicates that this decrease is caused by an increase in absorption resulting from an increase in the imaginary part of the index of refraction, and not by a change in thickness, or increased surface roughness giving rise to increased scattering. These results suggest that such optical-baffle materials will provide enhanced performance as a result of aging in the space environment.

6.
Phys Rev B Condens Matter ; 43(8): 6598-6601, 1991 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-9998101
8.
Phys Rev B Condens Matter ; 42(2): 1455-1457, 1990 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-9995564
10.
Phys Rev B Condens Matter ; 41(9): 6057-6060, 1990 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-9994491
11.
Appl Opt ; 29(3): 332-3, 1990 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-20556104

RESUMO

We report and analyze the infrared properties of single crystal MgO, an important substrate for high T(c), superconducting films, from 10 to 280 cm(-1) and 20-300 K.

15.
Phys Rev B Condens Matter ; 38(8): 5565-5567, 1988 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-9946997
16.
Phys Rev B Condens Matter ; 38(3): 2212-2214, 1988 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-9946521
19.
Phys Rev B Condens Matter ; 33(7): 4557-4559, 1986 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-9938917
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...