JPS63304674A - Thin film semiconductor element and manufacture thereof - Google Patents

Abstract

PURPOSE:To cut down the cost of the element for solar battery by a method wherein a power supply using a solar battery is connected to be a DC bias power supply of a temperature sensing element. CONSTITUTION:A photoresisting film 2, lower electrodes 3, terminals 4-6 and a thin film resistor 7 are formed on a phototransmitting substrate 1; next amorphous semiconductor thin films 8, 9 with PIN junction at the substrate temperature are formed; and then upper electrodes 10, 11 as the backside electrodes are formed. The lower electrodes 3, the upper electrodes 10 isolated taking the insular shape and the amorphous semiconductor thin film 8 as common films are formed into a solar battery 12 by series connecting to multiple cells. When the solar battery of PIN junction is formed in the order of P.I.N, the terminal 5 becomes a terminal with the positive polarity and the terminal 4 becomes a terminal with the negative polarity corresponding to a circuit diagram. Consequently, a PIN diode 13 comprising single cell composed of the amorphous semiconductor film 9 and the upper electrode 11 is connected to be impressed with a bias voltage in the reverse direction by the solar battery 12 which is series-connected to multiple cells using a transparent conductive film or the photoresisting film 2 as a lower electrode. Through these procedures, the cost of the element for solar battery 12 can be cut down.

Description

[Detailed Description of the Invention] Page 2 Industrial Fields of Application The present invention is used for thermometers and temperature sensing elements powered by solar cells, and includes composite products such as solar calculators with thermometers and wireless remote controllers with temperature sensors for air conditioners. The present invention relates to a thin film semiconductor device used in, for example, a thin film semiconductor device and a method for manufacturing the same.

BACKGROUND OF THE INVENTION Monocrystalline silicon and polycrystalline silicon have long been used as solar cell materials, and recently CdS/CdTe, amorphous silicon, and the like have been used for thin-film solar cells. Among thin-film solar cells, hydrogenated amorphous silicon thin-film solar cells can be formed on various substrates such as glass, alumina, alumite stainless steel, and polyimide at low temperatures below 250°C by plasma CVD. can.

On the other hand, metal resistors, thermocouples, thermistors, etc. are most widely used as cold temperature sensors that are easy to process electrical signals. Among them, thin film temperature sensors used for the purpose of reducing heat capacity and speeding up thermal response include thermistors that utilize temperature changes in the resistance of SiC thin film 3-perilla resistors formed by high-frequency sputtering, and amorphous Thermocouples are known that utilize the thermal superpower generated when silicon and metal are bonded together. However, there is no conventional example in which a solar cell and a temperature sensing element are formed on the same substrate using the same amorphous semiconductor thin film, and there is also no example in which the thick battery is connected as a DC bias power source for the temperature sensing element.

Problems to be Solved by the Invention Conventional temperature sensing elements, both bulk semiconductor elements and thin film semiconductor elements, have the disadvantage of high manufacturing costs. In addition, even in the case of thermometer solar remote controllers that control air conditioners, etc., which have solar cells and temperature sensing elements installed separately, the cost of installing and wiring the solar cells and temperature sensing elements, and the high power consumption The problem was that a large-area solar cell was required to operate the sensing element.

The present invention solves these problems by forming a solar cell and a temperature sensing element on the same substrate by a thin film semiconductor deposition method such as a plasma CVD method, and using the solar cell as a power source. Use a thermometer or temperature sensor. The purpose is to provide thin film semiconductor devices at low cost for use in solar thermometer calculators, solar remote controllers with temperature sensors for air conditioners, and the like.

Means for Solving the Problems The present invention provides P in a part of an amorphous semiconductor thin film such as hydrogenated amorphous silicon formed on the same substrate by a plasma CVD method or the like.
Forming solar cells such as iN junctions and Schottky junctions, and shielding part of the amorphous semiconductor thin film that can be formed in almost the same process, we can measure the temperature characteristics of the reverse saturation current of thermistors, thermocouples, or PiN junctions. This is to form a temperature sensing element that applies semiconductor characteristics such as. As a light shielding means here, a Cr film formed by electron beam evaporation or sputtering is used.
If necessary, a continuous light film such as N i Cr or SfO or 5j
Use 3N4 insulation or a passivation film made of opaque epoxy resin.

Device formation for solar cells and temperature sensing elements can be performed using almost the same plasma CVD process, electrode deposition process, and mask process, and the formation of amorphous semiconductor thin films can also be performed simultaneously using common equipment. This can be done in a film or two film formation steps. Electrical connections between solar cells and temperature sensing elements and formation of thin film resistor circuits can be simultaneously realized using the same mask process.

An amorphous semiconductor thin film that has a working semiconductor junction and is not light-shielded functions as a solar cell by generating photocarriers generated by incident light and separating them by the internal electric field of the semiconductor junction to generate photovoltaic force.

On the other hand, the light-shielded amorphous semiconductor thin film outputs various temperature characteristics as a semiconductor, such as thermistor characteristics, forward current temperature characteristics, and reverse saturation current temperature characteristics, as electrical signals. A planar electrode is deposited on a single layer or an i-layer doped with a small amount of impurity, and when a DC voltage is applied, it functions as a thermistor whose resistance value changes depending on the temperature. Also P
When a reverse bias voltage is applied to the iN junction, the reverse saturation current changes in proportion to the square root of the carrier concentration as the temperature rises. In both cases, the signal current consumption is small because the amorphous semiconductor thin film has high resistance, and the planar type DC voltage or reverse bias voltage of the PiN junction is applied using a DC power supply using a 61-inch solar cell. This becomes possible easily.

Embodiment A perspective view of a typical embodiment according to the present invention is shown in FIG.
FIG. 2 shows a circuit diagram of an embodiment of the present invention using a solar battery power source that combines a secondary battery and a constant voltage diode.

In FIG. 1, a Cr or N film with a thickness of 200 OA or more is deposited on a transparent substrate 1 made of glass with a thickness of 0.1 to 2 layers.
i Cr light shielding film 2 and thickness 7008~2100 5%
A transparent conductive lower electrode 3, a terminal 4, a terminal 5, a terminal 6, and a thin film resistor made of SN203 doped with SnO2 are formed using a vacuum evaporation method or a sputtering method with an oxygen partial pressure of about 1O-4 Torr. did. Next, a plasma CVD method using RF glow discharge or a photoCVD method is used.
1) (411GeH4'I S 12H6 etc. is the main raw material and H2 diluted mixed gas is decomposed in a vacuum container, 1
Amorphous semiconductor thin films 8 and 9 having PiN junctions were formed at a substrate temperature of 50° C. to 250° C. to a thickness of 0.4 μm to 1 μ7. The P layer with a thickness of 1008 to 150 people uses B2H6 gas diluted with H2, and the N layer with a thickness of 150 to 300 people uses PH3 gas diluted with H2 as an impurity gas. Doping was performed by mixing B2H6 and PH3 at a concentration of 1% to 2%.

Furthermore, as a back electrode, the thickness is 20008~600080AJ.
2, Ti, or a stack of these upper electrodes 10.11
was formed by vacuum evaporation or sputtering.

These thin films can be easily patterned using a metal mask during film formation.

A solar cell 12 was formed by connecting a plurality of cells in series using the lower electrode 3 and the upper electrode 10 separated into island shapes and the amorphous semiconductor thin film 8 as a common film. In Figure 1, Pi in the order P・i−N
When an N-junction solar cell is formed, the terminal 5 becomes a positive terminal, and the terminal 4 becomes a negative terminal, corresponding to the circuit diagram in FIG. 2. Therefore, a single-cell PiN diode 13 composed of an amorphous semiconductor film 9 and an upper electrode 11 with a transparent conductive film or a light-shielding film 2 as a lower electrode is a solar cell 12 connected in series with a plurality of cells, and a bias voltage is applied in the opposite direction. connected so that The reverse saturation current of one cell of an amorphous semiconductor thin film PiN diode is stable in the range of 1 to 1 ov when the film thickness is usually 1 μm or less. If it is less than 1V, saturation is insufficient, and if it is more than 1O2, a breakdown current will flow and the temperature sensing element will not operate as desired. On the other hand, the open circuit voltage of one crystalline solar cell is approximately o-eV under 2 oofl construction,
The operating voltage is about 85 V under AMl (100 mW/crrt), and the operating voltage is 60% to 70% of the open circuit voltage, so the operating voltage per cell is 0.36 V to 0.6 V.
It is.

Therefore, if the number of series-connected cells of the solar cell is three times or more the number of series-connected cells of the temperature sensing element, a stable saturation current value with a reverse voltage of 1■ or more can be obtained.

In the present invention, when the solar cell on the power source side and the temperature sensing element on the side that uses the power source are connected and wired on the same board as in the embodiment shown in FIG. A configuration in which no backflow prevention diode is used between the secondary battery 14 and the constant voltage diode 15 is also possible. Even if the amorphous thin film solar cell 12 is forward biased by the secondary battery 14 in the dark, the leakage current in the forward direction is small, so it can be ignored and does not require a backflow prevention diode. . Furthermore, there is no need to compensate for the voltage loss o, 3v-0, 4V of the backflow prevention diode, making it possible to design a more compact solar cell.

FIG. 3 shows another embodiment according to the invention. In the same manner as shown in FIG. 1, a metal lower part made of Cr with a thickness of 2000mm to 1μ is placed on the light-guiding insulating substrate 16, such as an alumite substrate with a thickness of 0.2 mm to 0.5 mm or a ceramic substrate with a thickness of 0.5 mm to 2 mm. Electrodes 17 and 18 were provided, and S diluted with H2
x H4 is decomposed by RF glow discharge and the substrate temperature is 15.
Amorphous semiconductor thin film having a PiN junction by sequentially forming a P layer with a thickness of 2008 to 400 at 0C to 25oC, an I layer of 0.4μ to 1μ @ 10o to an N layer with a thickness of 200 After forming a film 21, transparent electrodes 22 and 23 and 24 and
25@26 was deposited to obtain ohmic contact. Next, a part of the N layer and the first layer of the temperature sensing element were removed by dry etching using a mixed gas of CF4 and 02, and the amorphous semiconductor thin film 2o was formed so as to function almost as an i layer. bottom two layers 10
``-'' can increase the resistance by reducing B through diffusion.A light-shielding resin is placed on the amorphous semiconductor thin film 2Q, which serves as the temperature sensing element, except for the terminal portions of the transparent electrodes 23 and 24. A transparent resin was screen printed on top of the solar cell as passivation.

FIG. 4 is a circuit diagram in which a secondary battery 26 and a constant voltage diode 2 are connected to the embodiment shown in FIG. A thin film resistor 30 for reading out changes was connected. Third
In the embodiment shown in the figure, the amorphous semiconductor thin film 2o has a high resistance, so it functions as a temperature sensing element with low power consumption, and is suitable for using a solar cell as a DC power source as in the embodiment shown in FIG.

Effects of the Invention According to the present invention, a solar cell and a temperature sensing element can be formed on the same substrate, or a solar cell and a temperature sensing element can be manufactured simultaneously in the same manufacturing process, resulting in extremely low cost.

In addition, since an amorphous semiconductor thin film is used, the current consumption of the temperature sensing 11" element is small, a small solar cell on the same substrate can be used as a power source, and connection circuits and thin film resistance elements can also be used. Since they can be formed on the same substrate, excellent effects such as low cost and high reliability can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a typical embodiment according to the present invention;
The figure is a circuit diagram including a power supply circuit using the embodiment of FIG. 1, FIG. 3 is a perspective view of another embodiment according to the present invention, and FIG.
FIG. 3 is a circuit diagram including a power supply circuit using the illustrated embodiment. DESCRIPTION OF SYMBOLS 1... Translucent substrate, 2...-Light-shielding film, 3... Lower electrode, 4,5.6--Terminal, 7...-Resistor, 8,9-
-Amorphous semiconductor thin film, 10, 11-...Top electrode. Name of agent: Patent attorney Toshio Nakao and 1 other person11
11, lE--]]21-≧4 it4--2
Dog viewing

Claims (3)

[Claims] (1) A part of the amorphous semiconductor thin film formed on the substrate constitutes a solar cell, while a part of the amorphous semiconductor thin film formed on the substrate in a shielded manner constitutes a temperature sensing element, and A thin film semiconductor device, characterized in that a power source using a solar cell is connected to serve as a DC bias power source for the temperature sensing device. (2) The thin film semiconductor device according to claim 1, wherein the temperature sensing element has the same semiconductor junction as the solar cell and has temperature characteristics of a reverse saturation current reversely biased by the solar cell. . (3) A part of the amorphous semiconductor thin film having a semiconductor junction formed simultaneously on the same substrate by a plasma CVD method forms a solar cell, and the other part forms a temperature sensing element. A method for manufacturing thin film semiconductor devices.