JPS58118173A - Infrared ray detection device - Google Patents

Abstract

PURPOSE:To approach the titled device to a planar structure resulting in a large restriction of crystal defects by a method wherein, after an electrode making an ohmic junction with an accumulation part is provided on a semiconductor substrate having a charge accumulation part and a charge transfer part, then thereon a polycrystalline Si layer wherein an impurity is doped only at the detection element part is formed, then a Schottky electrode is provided thereon. CONSTITUTION:On the P type Si substrate 30, a CCD part 31, the signal charge accumulation part 32, and a channel stop part 33 are formed by an impurity diffusion, and, on a transfer gate oxide film constituted of SiO2 34, an Al transfer gate 35 is provided resulting in the formation of the signal charge transfer part. Next, except for a part of the accumulation part 32, a PSG film 36 is adhered, and the insulation is kept between the infrared ray detection element constituted of a semiconductor side Mo electrode 39 provided thereon, a P type polycrystalline Si layer 37, and a metal side Pt electrode 38, and the gate 35. Thereafter, boron is doped only at the part positioned on the electrode 39 of the layer 37, and conductivity is provided to only the layer 37 immediately under the electrode 38 constituting the Schottky junction.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a high-density infrared detection device having a Schottky type infrared detection element.

Prior art and its problems / It is well known that the 1-loaded element using Recon (8i) as a substrate material is used for various purposes such as pupil image, signal processing memory, etc. In detectors, it is also used to transfer the prisoner's code of hybrid infrared detectors.

Conventionally, in a hybrid infrared detector, an infrared sensing element assembly in which a plurality of photovoltaic infrared sensing elements are arranged on the surface of a single multi-component semiconductor substrate and a charge transfer element made of a silicone are fixed to each other and integrated. A new structure was proposed. The infrared detector stomach according to this proposal is manufactured by using a metal bumper 12 protruding from the pn junction of the infrared sensing element, and fixing the sensing element to the charge transfer element. Ru.

FIG. 1 is a sectional view showing the structure of the infrared detecting device of the nine prior invention mentioned above. The infrared detecting element has a thin plate 1 made of a multi-component semiconductor as a substrate, and mesa-shaped light receiving parts 101, 102, 103, . Inside each mesa, there is a pn junction surface JIJ2, r3,
..., which converts the incident infrared rays into electrical signals at this joint surface.

A film 22 of silicon dioxide (Si02) and reverse conduction type expansion layers 301, 302, 3 which become input diodes are formed on one surface of the FllllI charge transfer device 20 and 81 substrate 21.
03, and an electrode group is formed on a 5in2 plate 22.

In this structure, the light receiving sections 101, 102, 103...
Since the charge transfer element 20 is pressure-bonded to the top of the mesa through the top of the mesa, some of the defects occur near the top of the mesa, and some of them are p-n junctions J1 and tJ2.
+J3...(Exceeds.) If this condition occurs, there is a drawback that the performance of the infrared detection element will be significantly degraded.

OBJECTS OF THE INVENTION The present invention solves the above problems and provides an infrared sensing device in which an infrared S sensing element is formed on an element substrate like a visible light imaging device.

Summary of the Invention The present invention provides an electrode that is ohmically connected to the charge storage section on a charge transfer type semiconductor element substrate having a charge storage section and a charge transfer section, and an impurity is doped only in the sensing element section on this electrode. This is an infrared detection device having a structure in which a polysilicon layer is formed and a soft key electrode is provided on the polysilicon layer.

Effects of the Invention According to the infrared detection device of the present invention, the occurrence of crystal defects can be significantly suppressed because it can be made to have a planar structure, and the performance of the infrared @ detection element is significantly improved compared to conventional ones. ditto can be made.

Embodiments of the Invention Hereinafter, embodiments of the present invention will be explained in detail with reference to the drawings. Figures 2 (FA) and (B) show the structure of one embodiment of the infrared d detection device according to the present invention as a sectional view and a top view, respectively. A CCD section 31 is placed on a P-type silicon plate 30. The Ifi charge storage section 32 and the channel stop section 33 are formed by diffusion of impurities such as implantation.
i02 Transfer gate oxidation/oxidation by CVD 11134: An Al transfer gate 35 is provided to constitute a signal charge transfer section. By devoting the PSG layer 36 by removing a part of the signal '1 load storage section 32 thereon, the gap between the semiconductor side electrode Mo 39 of the Schottky type infrared lfs@sense element formed thereon and the transfer gate 35 is further removed. maintains insulation. The infrared detection element is 1. Toto semiconductor side electrode Mo39. It is composed of p-type polysilicon 37 and metal side pt electrode 38.

The semiconductor @electrode Mo 39 is in ohmic contact with the p-type polysilicon 37 and the signal charge storage section 32, so that the f1 charge photoelectrically converted at the Cyranodo-Key junction is immediately introduced into the signal charge storage section 32. There is. After forming the semiconductor-side electrode Mo 39, the p-bedded polysilicon 37 is formed by depositing polysilicon with a low carrier density on the entire surface of the substrate, and applying p to the polysilicon on the semiconductor-side electrode Mo 3g.
Select and implant boron, for example, to form a mold. At this time, the semiconductor side electrode M039 serves as a Heinbla mask, and no impurity is implanted into the underlying PSG [36]. 4
In addition, the polysilicon 40 which is not implanted at an M degree that can be detected by infrared rays, for example 77 degrees, has a higher specific resistance than the implanted polysilicon 37, and plays the role of element isolation. An infrared transmitting Pt electrode 38 corresponding to the metal electrode of the Sirotchi junction is formed on the entire surface of the polysilicon 37, 40, and the electrode is biased to a constant voltage during the infrared detection period.

Such an infrared @ detection device does not have the difficulty of adhering the infrared detection element and the charge transfer element in the infrared detector of the prior invention mentioned above, and the manufacturing method is also very simple. moreover,
The infrared sensing element in this infrared sensing device is made by implanting impurities such as boron into polysilicon 37, 40, and is very easy to separate. Furthermore, with the introduction of this structure, there is no need to fabricate infrared sensing elements in a strict manner, and the planar type makes it easier to manufacture infrared sensing elements.
It is very advantageous in that it can be expected to significantly improve fg of b.

Other Embodiments of the Invention In one practical example of the present invention, an infrared sensing element with pt
1 pole 38 is on the infrared light incident side, but polysilicon 3
It is also possible for 7 to be infrared light incident @VC, in which case a Pt electrode 38 is formed at the position of the pole 39, and a photoconductive electrode, such as ITO, is formed at the poly 7 silicon 37. 40 is debosed on the entire surface to form four infrared detection elements.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a main part showing the structure of a conventional infrared detection device, and Fig. 2 (tA) and @ are a cross-sectional view of a main part and a main part showing the structure of an embodiment of an infrared detection IT according to the present invention, respectively. FIG. 30... Piml silicon substrate, 31... CCD section, 32... Signal charge storage section, 33... Channel stop section, 34... Transfer game beaking smell, 35... Transfer gate, 36 ...PSG@, 37...p-type polysilicon implanted with impurities, 38...pt electrode, 3
9...Mo lj pole. 40・Polycone with no impurities implanted. Agent: Patent attorney Nori Chika Tsubo (1 other person) Figure 1 Figure 2 3423'? 3'/ 32" 33

Claims (1)

[Scope of Claims] 1111 A load-transmitting semiconductor element substrate having a charge accumulation section and a charge transfer section; A first electrode formed on the load accumulation part and connected to the load accumulation part; and a first electrode formed on the load accumulation part; and a polysilicon layer doped with impurities only in the book-chip portion;
An infrared detecting device comprising a second electrode which is formed on the polysilicon layer and formed by a Schottky junction with the polysilicon layer. 12) The infrared phase detection device according to claim 1, wherein the first electrode is a molybdenum electrode. (3) The infrared detecting device according to item 1 of the scope of patent request #I#, characterized in that the second electrode 1d is a white ft electrode.