DD203433A1 - ANTI-REFLECTION COATING UV-SENSITIVE DETECTORS - Google Patents

Abstract

The invention relates to an antireflection coating for UV-sensitive detectors based on semiconductors. The object of the invention is a detector with an increased efficiency in the wavelength range of 200-400 nm, which is to be achieved by the fact that the transmission minima in the spectral range of the UV light are less pronounced by changing the antireflection layer. According to the invention, it is achieved that the antireflection coating applied to a silicon detector made of known antireflection coatings is wedge-shaped or represents a geometric arrangement of several, in particular two, layer thicknesses.

Description

234478

Title: Antireflection coating of UV-sensitive detectors

Field of application of the invention;

The invention relates to the field of semiconductor-based radiation detectors and, more particularly, to UV-sensitive detectors.

Characteristic of the Known Technical Solutions: It is known to apply an additional coating with reflection-reducing properties to the surface of the semiconductor body facing the light entrance, below which the radiation-onsensitive on-topganate, so as to reduce the loss of the radiation reflected by the semiconductor body. Such coatings as silicon monoxide (SiO) ₁ silicon dioxide (SiO 2) and magnesium fluoride (MgF 2) are known from the optical industry. Also find use alumina (Al ^ O-) and silicon nitride (S3 .., N ₄ ) DE-CS 2022896.

Usually detectors are provided with the above-mentioned Antireflexionsbela conditions uniform layer thickness. The transmission coefficient of such coated detectors has deeply pronounced minima in the range of UV light (2OG 400 nm), whereby the efficiency of these detectors in the range of UV light in the regions of the transmission minima is very high

is low

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Object of the invention:

The object of the invention is a detector with an increased efficiency in the wavelength range of 200-400 nm compared to known antireflection-coated detectors.

Explanation of the essence of the invention:

The technical problem to be solved by the invention is to change the Antireflexior.sbeschichtung such that the Minirna in Spektralbsreich of the UV light, the curve representing the transmission in dependence on the wavelength, are less deeply pronounced and As a result, the efficiency of the detectors in the UV range is increased. The technical object is achieved by a silicon body, on whose surface a photoelectric transition is formed and this surface is provided with a known antireflection coatings Antireflixionsschicht, according to the invention in that the layer thickness of the antireflection layer increases continuously or the antireflection layer a geometric arrangement of several, in particular two layer thicknesses represents,

Ausführuncsbeispiel:

The invention will be explained below with reference to drawings in more detail »

Fig.ur i shows a silicon detector with an inventive anti-reflection layer, the layer thickness "increases continuously.

FIG. 2 shows the curve of the transmission coefficient as a function of the wavelength at different layer thicknesses of the antireflection layer . In FIG. 1, an antireflection layer of silicon dioxide is applied to the silicon detector, the layer thickness of the antireflection layer increasing continuously from 100 .mu.m to 200 nm.

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Figure 2 shows the course of the curve of the transmission coefficient as a function of wavelength for a silicon detector with an anti-reflection coating of silicon dioxide with a constant thickness of 100 nm and for an inventive antiref lexionsbeschichtung with continuously increasing layer thickness of 100 nm to 200 nm.

For the antireflection coating according to the invention, it can be clearly seen that the depth of the minima in the spectral range of the UV light has been reduced in contrast to a traditional antireflection coating. The antireflection coating according to the invention achieves a partial compensation of the minima and maxima and thereby increases the efficiency of the detector in the region of the minima,

Figure 3 shows ways in which the antireflective layer of silicon dioxide is deposited on a silicon detector as a geometric arrangement of two layer thicknesses in order to achieve a high uniformity of the curve of the transmission coefficient as a function of the wavelength for a narrowly limited wavelength range. With a geometrical arrangement of a layer thickness of the antireflection coating of d ₁ '= 120 nm and a layer thickness d _? = 140 nm, wherein the areas of the different layer thicknesses are approximately equal, the minima and maxima of the transmission coefficients compensate each other such that for the wavelength range of the UV light, for example in the range of 200 nm - 300 nm, an approximately constant transmission coefficient. the magnitude of 0.45 is achieved.

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Claims (1)

- »- Z 3 A A 7 8 trfindungsanspruch: Antireflection coating UV-sensitive detectors, wherein the detector consists essentially of a silicon body, on one surface of which a photoelectric transition is formed and on this surface is provided from known antireflection coatings antireflection coating, characterized in that the layer thickness of the antireflection film on the detector continuously increases or the antireflection layer is a geometric arrangement of several, in particular two layer thicknesses. For this a page Zeichnuna