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4.5. Photolithographic microstructurization of a surface of crystals paratellurita

Reception of a relief of a demanded configuration in the dielectric and metal films superimposed on a surface of semiconductor or dielectric substrates, is the integral process of manufacturing techniques of integrated plans (IS).

It has gained the lithograph name. Lithograph is grounded on use of special high-molecular linkings - rezistov, possessing ability to change the properties under

Activity of a various sort of radiations - ultra-violet (photolithography), X-ray (rentgenolitografija), a stream of electrons

(elektronolitografija) and ions (ionic-beam lithograph) [189]

In microelectronics and optical lithograph are used fotorezisty, coating with a thin film the plate surface on which the image the Photoresistive film should be superimposed is exhibited in UF light then according to photo mask drawings on it the lighted and not lighted fields are formed. At display there is the selective removal rezista. The remained drawing fotorezista on a plate surface is used as a mask at carrying out of etching, metallization, transpiration and t.d. Applied in microelectronics [190].

Rezisty can be both negative, and positive. After action of an exhibiting irradiation the miscibility negative rezistov in developer decreases, and positive is incremented as is shown in drawing 4.25 [189].

fotorezisty are photosensitive materials with a miscibility changing under the influence of light. fotorezisty usually consist of three builders:

Photosensitive substances; film-forming substances;

Solvents.

In negative FR under the influence of light response of photoaffixion (photopolymerization) proceeds. At photopolymerization occurs traversal sshivka polymetric compound molecules therefore they are integrated, become three-dimensional, and their chemical firmness increases. In positive FR under the influence of light miscible linkings (photodecomposition) are formed. For realisation of this problem it is convenient to use intermixtures naftohinondiazidov (NHD) with fenolformaldegidnymi tars in organic solvents.

Drawing 4.25 - Plans of process of a photolithography with negative () and positive () fotorezistami

Key parametres FR are the light sensitivity, resolving ability, chemical firmness to traviteljam. Light sensitivity S is a quantity, return exposures, i.e. to quantity of the light energy necessary for irradiation FR to translate it in nonsoluble (measure - clearness of a relief). Resolving ability characterises ability FR to making of a relief of drawing with the underload sizes of devices. Resolving ability R is spotted by number of lines of the equal breadth which are parted by gaps of the same breadth and finding room in one millimetre (negative FR) or miscible (positive FR) a state. Chemical firmness is an ability of stratum FR to protect a surface of a substrate from action travitelja. Measure of firmness is time during which FR maintains activity travitelja till the moment of occurrence of such flaws as partial fracture, otslaivanie from a substrate, local dot rastravlivanie a stratum or 132

podtravlivanie it on boundary with a substrate. Firmness FR to chemical actions depends on type FR, its thickness, etc. [189,190].

Along with research problems of micromorphological changes of structure of a surface of the crystals caused in the core by influence of flaws, in our operation other aspect of use of chemical etching paratellurita, namely, for making of the superficial periodic structures of the given geometry was considered. Application of etching for making of optical devices of different function is not new so in operation [191] possibilities of use of processes of the aeolotropic etching of monocrystal silicon have been explored.

In comparison with traviteljami the isotropic activity, for example HF/HNO3/CH3COOH, aeolotropic traviteli (the GAME, tetramethyl ammonium Indroxiden other) Are extremely inertial at etching of planes (Ill) unlike other facets with much bigger velocity of dissolution. Possibility of reception of various periodic microlateral views, in particular, lateral views of a sawtooth view is as a result created. However, in case of silicon operation possibility in a visible part of an optical gamut since silicon is transparent only the personal computer a gamut is excluded. This restriction acts in film at use of two-refracting crystals of the Icelandic spar (calcite), transparent in visible field. Mechanical properties of a calcite low enough (softness, fragility, raskalyvaemost), that impedes its machining. This problem is successfully overcome at the aeolotropic chemical etching that allows to develop new perspective types of polarisation and diffraction optical devices. At the same time it is necessary to consider, that natural reserves of the Icelandic spar are exhausted almost completely in this connection we had been worked possibility of its replacement by artificial crystals paratellurita, possessing high optical performances. For making of necessary lateral views of a surface, the technology has been used
The photoresistive microstructurization, widely used in the up-to-date microelectronics.

For making of the superficial periodic structure on a crystal paratellurita in our operation has been used dry sheet fotorezist ORDYL ALPHA 350. On shlifovannuju and the polished plate which has been cut out from monocrystal TeO2, it was superimposed fotorezist and a copper net which were exposed to the Uf-irradiation. Development was carried out in solution Na2CO3 (a sodium carbonate) at the control of the gained effect on metallographic microscope МИМ-8. Then Uf-irradiation procedure after which etching was spent to 5 % solution KOH (caustic kali) was iterated. In drawing 4.26 the gained periodic structure on TeO2 is presented,

Drawing 4.26 - the Image of a copper net (JEOL 6610) (), periodic structure on TeO2 (МИМ-8) (), periodic structure on TeO2 (JEOL 6610)

In chapter 4 the dislocation structure of crystals paratellurita [110], [001] is explored, application of a photoelastic analysis for revealing of dislocations in crystals paratellurita is featured, is spent kristallomorfologichesky the analysis of all macroscopical facets of monocrystals paratellurita, sectorial allocation of dislocations in sections of crystals paratellurita is revealed. Possibility of making of microlateral views on a surface of monocrystals paratellurita is shown by a photolithography method.

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A source: Ivanova Alexandra Ivanovna. Micromorphology of a surface and dislocation structure of large-sized optical crystals of germanium and paratellurita. The dissertation on competition of a scientific degree of the candidate of physical and mathematical sciences. Tver - 2015. 2015

More on topic 4.5. Photolithographic microstructurization of a surface of crystals paratellurita:

  1. Chapter 4. MICROMORPHOLOGY of the SURFACE of CRYSTALS paratellurita
  2. Ivanov Alexander Ivanovna. Micromorphology of a surface and dislocation structure of large-sized optical crystals of germanium and paratellurita. The dissertation on competition of a scientific degree of the candidate of physical and mathematical sciences. Tver - 2015, 2015
  3. Ivanov Alexander Ivanovna. MICROMORPHOLOGY of the SURFACE And DISLOCATION STRUCTURE of LARGE-SIZED OPTICAL CRYSTALS Germany And paratellurita. The dissertation AUTHOR'S ABSTRACT on competition of a scientific degree of the candidate of physical and mathematical sciences. Tver - 2015, 2015
  4. 4.1. Morphology of crystals paratellurita and its communication with a crystallisation kinetics
  5. 4.3. Flaws of structure of crystals paratellurita and communication of their formation with rostovoj a kinetics
  6. 3.3.1. The kinetic coefficients at growth of crystals paratellurita
  7. Flaws of structure and optical anomalies in crystals paratellurita and germanium
  8. optical properties of the uniaxial crystals paratellurita, iiobata lithium and SBN, as objects for examinations by a conoscopy method
  9. cultivation of crystals paratellurita an expedient Chohralsky
  10. 1.5. The basic performances and scopes of optical crystals of germanium and paratellurita
  11. CHAPTER 4. INFLUENCE OF THE KINETICS ON MORPHOLOGY AND FORMATION OF FLAWS STUKTURY OF CRYSTALS paratellurita AND GERMANY
  12. Gavaljan Mamikon JUrevich. Influence of crystallographic orientation and the impurity composition on optical, the dielectric and teplofizicheskie performances of crystals of germanium and paratellurita. The dissertation on competition of a scientific degree of the candidate of physical and mathematical sciences. Tver - 2016, 2016
  13. Gavaljan Mamikon JUrevich. Influence of crystallographic orientation and the impurity composition on optical, the dielectric and teplofizicheskie performances of crystals of germanium and paratellurita. The dissertation AUTHOR'S ABSTRACT on competition of a scientific degree of the candidate of physical and mathematical sciences. Tver - 2016, 2016
  14. Vorontsova Elena Jurevna. the SHAPE ISOCHROME In KONOSKOPICHESKY PATTERNS of the UNIAXIAL CRYSTALS AT ANY CROSS ORIENTATION of the NORMAL LINE To the SURFACE And the OPTICAL AXIS. The dissertation on competition of a scientific degree of the candidate of physical and mathematical sciences. Tver - 2018, 2018
  15. 2.6 Influence of surface defects of the polished surface of copper on a reflectivity in IK - fields
  16. Vorontsova Elena Jurevna. the SHAPE ISOCHROME In KONOSKOPICHESKY PATTERNS of the UNIAXIAL CRYSTALS AT ANY CROSS ORIENTATION of the NORMAL LINE To the SURFACE And the OPTICAL AXIS. The dissertation AUTHOR'S ABSTRACT on competition of a scientific degree of the candidate of physical and mathematical sciences. Tver - 2018, 2018