JP2002523768A - Bolometer with meandering stress-harmonic part - Google Patents

Abstract

(57) Abstract An infrared bolometer includes an active matrix level, a support level, a pair of posts, and an absorption level. The active matrix level includes a substrate having a pair of connection terminals. The support level includes a pair of support piers, each of the support piers includes a conductive wire formed thereon, wherein one end of the conductive wire is electrically connected to a corresponding one of the connection terminals. ing. The absorption level includes a meandering bolometer element surrounded by an absorber and a meandering stress-conditioning portion formed below the absorber. The meandering stress harmony portion formed at an angle of 90 degrees and formed of the same material as the meandering bolometer element to form a compressive stress uniformly distributed in the absorber. Is formed, and the absorption level does not bend, so that optimum absorption efficiency can be ensured.

Description

DETAILED DESCRIPTION OF THE INVENTION

TECHNICAL FIELD [0001] The present invention relates to an infrared bolometer, and more particularly to an infrared bolometer having a meandering stress-harmonic portion.

BACKGROUND OF THE INVENTION A bolometer is an energy detector that uses the resistance of a material (a so-called bolometer element) to change due to radiant heat flux. The bolometer element is made of metal or semiconductor. If the bolometer element is a metal, the change in resistance is fundamentally due to a change in carrier mobility, and the change in resistance decreases with increasing temperature. In contrast, in high resistivity semiconductor bolometer elements, the carrier density varies exponentially with temperature, and higher detection capabilities can be obtained. However, it is difficult to manufacture a bolometer element made of a thin film semiconductor for constructing a bolometer.

FIGS. 1 and 2 are perspective and sectional views, respectively, showing a bolometer 100 that includes an active matrix level 110, a support level 120, at least one pair of posts 170, and an absorption level 130. And

An active matrix level 110 includes a substrate 112 containing an integrated circuit (not shown),
It includes a pair of connection terminals 114 and a protective layer 116. Each connection terminal 114 made of metal is located above the substrate 112. For example, the protective layer 116 made of silicon nitride (SiNx)
Covers the substrate 112. The pair of connection terminals 114 are electrically connected to an integrated circuit.

The support level 120 includes a pair of support piers 140 made of, for example, an insulating material such as silicon oxide (SiO ₂ ), and a conductive line 165 is formed on each support pier 140. One end of the conductive wire 165 is electrically connected to the corresponding connection terminal 114 via the via hole 155.

The absorption level 130 includes a bolometer element 185 made of titanium (Ti), an absorber 195 made of an insulating material such as silicon oxide (SiO ₂ ) or silicon nitride oxide (SiOxNy), An infrared absorbing coating 197 formed on the body 195. Bolometer element 185 takes a meandering configuration to increase its own resistance.

[0007] Each post 170 is formed between an absorption level 130 and a support level 120. Each post 170 is made of a metal such as titanium (Ti), and has a conduit 172 surrounded by an insulating material such as silicon oxide (SiO ₂ ) or silicon nitride oxide (SiOxNy). Including. The top end of the conduit 172 has a meandering bolometer element 185
And the lower end of the conduit 172 is electrically connected to the conducting wire 165 on the support pier 140, so that both ends of the meandering bolometer element 185 at the absorption level 130 are It is electrically connected to the integrated circuit of the active matrix level 110 via the tube 172, the conductive line 165, and the connection terminal 114. When exposed to infrared radiant heat, the resistance of the serpentine bolometer element 185 changes, thus causing the voltage and current to change. The changed current or voltage is amplified by an integrated circuit, and the amplified current or voltage is detected by a detection circuit (not shown).

The infrared absorption bolometer 100 described above has certain disadvantages. For example, because absorption level 130 is structurally asymmetric, ie, the length of bolometer element 185 formed in the column direction is different from the length of bolometer element 185 formed in the row direction, FIG. As shown in (1), the compressive stress formed inside the absorber 195 is unevenly distributed, and the absorber 195 bends in the longitudinal direction, thereby reducing the overall absorption efficiency of the infrared bolometer 100.

(Disclosure of the Invention) Accordingly, the present invention has been made in view of such a problem, and an object of the present invention is to eliminate the effect of compressive stress unevenly distributed inside the absorber. It is an object of the present invention to provide an infrared bolometer including a meandering stress harmonizing part.

According to the present invention, in order to achieve the above object, an active matrix level having a substrate and at least a pair of connection terminals, each supporting pier includes a conductive wire, and one end of the conductive wire corresponds to the active bridge level. A support level electrically connected to a connection terminal, a support level having at least a pair of the support piers, an absorption level having a stress harmony section, an absorber, and a bolometer element, each of the support level and the support level; A conduit located between the bolometer elements, the end of the bolometer element of the absorption level being electrically connected to a corresponding connection terminal via the corresponding conduit and a conductive line. An infrared bolometer comprising at least a pair of posts connected is provided.

BEST MODE FOR CARRYING OUT THE INVENTION FIGS. 4 and 6 are cross-sectional views illustrating an infrared bolometer 200 according to two embodiments of the present invention, and FIGS. 5 is a front view illustrating an absorption level 230. FIG. 4 to 7, the same reference numerals indicate the same parts.

According to a first embodiment of the present invention, the bolometer 200 of the present invention shown in FIG. 4 includes an active matrix level 210, a support level 220, at least one or more posts 260, and an absorption level 230. .

The active matrix level 210 includes a substrate 212 containing an integrated circuit (not shown),
At least one or more connection terminals 214 and a protective layer 216 are included. The connection terminal 214 made of metal is located above the substrate 212 and is electrically connected to the integrated circuit on the substrate 212. As an example, a protective layer 216 made of silicon nitride (SiNx)
Is covered.

The support level 220 may include, for example, silicon oxide (SiO ₂ ) or silicon nitride oxide (
It includes a pair of supporting piers 240 made of an insulating material such as SiOxNy) and at least a pair of conductive wires 255 made of a metal such as titanium (Ti). Each conduction line 255
One end of the conductive wire 255 is electrically connected to the corresponding connection terminal 214 via the via hole 245, which is located above the corresponding support pier 240.

The absorption level 230 includes a meandering bolometer element 28 surrounded by an absorber 295.
5, a meandering stress-conditioning portion 275 located below the absorber 295, and an infrared absorbing coating 297 located above the absorber 295. The absorber 295 is made of an insulating material such as silicon oxide (SiO ₂ ) or silicon nitride oxide (SiOxNy). The meandering bolometer element 285 is made of, for example, a metal such as titanium (Ti).

FIG. 5 is a plan view of the absorption level 230. The figure shows the serpentine bolometer element 285 and the serpentine stress-conditioning portion 275 through the overlapping infrared absorbing coating 297 and absorber 295. The meandering stress harmonizing section 275 and the meandering bolometer element 285 are of the same shape and made of the same material. When viewed from the front, the meandering bolometer element 285 is located at an upper part with respect to the meandering stress matching part 275 and is formed at an angle of 90 degrees.

Returning to FIG. 4, each post 260 is formed between an absorption level 230 and a support level 220. Each post 260 includes a conduit 262 made of a metal such as titanium (Ti) surrounded by an insulating material 264 such as silicon oxide (SiO ₂ ) or silicon nitride oxide (SiOxNy). The upper end of the conduit 262 is electrically connected to one end of the serpentine bolometer element 285, and the lower end is connected to the corresponding support pier 2
The ends of the meandering bolometer element 285 at the absorption level 230 are electrically connected to the conductive line 255 formed on the upper part of the 40 through the conduit 262, the conductive line 255, and the connection terminal 214. And is electrically connected to the active matrix level 210 integrated circuit. When infrared energy is absorbed, the resistance of the serpentine bolometer element 285 is increased, and the increased resistance is detected by a detection circuit (not shown).

FIGS. 6 and 7 show another preferred embodiment of the present invention having some significant differences from the first embodiment described above. One of the 262 pairs of conduits has a meandering bolometer element 285
And one end of the pair of conduits 262 is a meandering stress harmonizing section 275.
Is electrically connected to one end. The other ends of the meandering bolometer element 285 and the meandering stress reconciliation unit 275 are electrically connected to each other. Therefore, the meandering bolometer element 285 and the meandering stress-conditioning unit 275 are electrically connected in series with each other, and the meandering stress-conditioning unit 275 acts as a bolometer element. Increase resistance.

In the infrared bolometer 200 of the present invention, in order to form a compressive stress uniformly distributed in the absorber 295, a lower portion of the absorber 295 is made of the same material as the meandering bolometer element 285 and has the same shape. In other words, a meandering stress harmonizing portion 275 formed at an angle of 90 degrees is formed. As a result, the absorption level 230 can ensure optimal absorption efficiency without bending.

While the preferred embodiments of the present invention have been described above, those skilled in the art will be able to make various modifications without departing from the scope of the present invention.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a conventional infrared bolometer.

FIG. 2 is a cross-sectional view of the infrared bolometer of FIG. 1 taken along plane AA.

FIG. 3 is a perspective view showing an absorption level of the infrared bolometer of FIG. 1;

FIG. 4 is a sectional view showing an infrared bolometer according to one embodiment of the present invention.

FIG. 5 is a plan view showing an absorption level of the infrared bolometer of FIG. 4;

FIG. 6 is a cross-sectional view illustrating an infrared bolometer according to another embodiment of the present invention.

FIG. 7 is a plan view showing an absorption level of the infrared bolometer of FIG. 6;

Claims (10)

[Claims] 1. An infrared bolometer having a three-layer structure, comprising: an active matrix level including a substrate and at least one pair of connection terminals; and a conductive line having one end electrically connected to each corresponding connection terminal. A support level having at least one pair of support piers, an absorption level including a stress harmony portion formed at a lower portion of the absorber and a bolometer element surrounded by the absorber, and between the absorption level and the support level. And at least one pair of posts each including a conduit surrounded by an insulating material, the upper end of the conduit being coupled to the absorption level, the lower end being electrically connected to the other end of the corresponding conductive line. Infrared bolometer characterized by being coupled to one another. 2. The bolometer according to claim 1, wherein the stress adjustment section has the same shape as the bolometer element. 3. The bolometer according to claim 2, wherein the bolometer element and the stress adjustment section have a meandering shape. 4. The bolometer according to claim 2, wherein the bolometer element and the stress adjustment section are made of the same material. 5. The bolometer according to claim 4, wherein the material comprises titanium (Ti). 6. The bolometer according to claim 4, wherein the stress adjustment section is formed at an angle of 90 degrees with respect to the bolometer element. 7. The apparatus according to claim 6, wherein each end of the absorption level bolometer element is electrically connected to a corresponding connection terminal via a corresponding conduit and a conductive wire. Bolometer. 8. One end of each of the bolometer element and the stress harmony portion,
The bolometer according to claim 6, wherein the bolometer element is electrically connected to a corresponding conduit, and the other end of the bolometer element and the other end of the stress adjustment unit are electrically connected to each other. 9. The bolometer of claim 1, wherein the active matrix level further includes a protective layer covering the substrate. 10. The bolometer of claim 1, wherein the absorption level further comprises an infrared absorbing coating formed on the absorber.