JPS61218106A - Heating resistor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a heat generating resistor, and more particularly to a thin film heat generating resistor formed by forming a resistive thin film as an AM element on the surface of a substrate.

Such a resistor is suitably used as an electric-thermal energy conversion element in various electronic or electric devices.

[Prior Art] Heating resistors conventionally used as relatively small electric-to-thermal energy conversion elements in electronic or electrical equipment include thin film types, thick film types, and semiconductor types. . Among these, thin-film types consume less power than other types and have relatively good thermal responsiveness, so their applications are gradually increasing.

The performance required of such a heating resistor is that it has good heat generation response to a predetermined electric signal, good thermal conductivity, and good heat resistance against its own heat generation. and that various types of durability (for example, durability against thermal history) are good.

However, in the conventional thin III type heating resistor, the above-mentioned performance is not necessarily satisfactory, and further improvement of the characteristics is desired.

[Object of the invention] In view of the above-mentioned prior art, one of the objects of the present invention
The first object is to provide a film heating resistor with improved thermal responsiveness.

Another object of the invention is to provide a thin film heating resistor with improved thermal conductivity.

Still another object of the present invention is to provide a thin film heating resistor with improved heat resistance.

Another object of the present invention is to provide a thin film heating resistor with improved durability.

[Summary of the Invention] The above objects are achieved by a novel thin film heating resistor according to the invention.

In the thin film heating resistor of the present invention, a functional thin film made of an amorphous material made of carbon atoms as a matrix and containing hydrogen atoms and a substance controlling electrical conductivity is formed on a substrate. The thin film is characterized by a non-uniform distribution of hydrogen atoms and/or substances governing electrical conductivity in the film thickness direction.

Hereinafter, the present invention will be explained in more detail with reference to the drawings.

FIG. 1 is a partial sectional view showing the structure of an embodiment of the heating resistor of the present invention.

In this figure, 2 is a base body, and 4 is a membrane for realizing functionality, that is, resistance.

In the present invention, there is no particular restriction on the material of the substrate 2, but in practice it has good adhesion with the functional thin film 4 formed on its surface, and during the formation of the functional thin film 4 and during use. A material having good durability against the heat generated by the functional thin film 4 is preferable. Further, it is preferable that the base body 2 has a higher electrical resistance than the functional thin film 4 formed on its surface.Furthermore, in the present invention, depending on the purpose of use of the resistor, the base body 2 may be made of a thermally conductive material. Small ones or ones with high thermal conductivity can be used.

Examples of the substrate 2 used in the present invention include those made of inorganic materials such as glass, ceramics, and silicon, and those made of organic materials such as polyamide resin and polyimide resin.

In the present invention, the monofunctional thin film 4 is made of an amorphous material having carbon atoms as its base material and containing hydrogen atoms and a substance controlling electrical conductivity. Substances that control electrical conductivity include so-called impurities in the semiconductor field, that is, p-type impurities that give p-type conductivity characteristics, and ny! that give n-type conductivity characteristics. Li impurities are available. P-type impurities include atoms belonging to Group Ⅰ of the periodic table of elements, such as B and AI.
, Ga, In, TI, etc., with B and Ga being particularly preferred.N-type impurities include atoms belonging to Group V of the periodic table of elements, such as P, As, Sb, Bi, etc., and in particular P, A
s is preferred, and these may be used alone or in combination.

The content of hydrogen atoms in the functional thin film 4 is appropriately selected depending on the purpose of use of the resistor so as to obtain desired characteristics, and is preferably o. 0005 to 20 atomic %, preferably 0.001 to 10 atomic %.

The content of the electrically conductive substance in the thin film 4 is appropriately selected depending on the purpose of use of the resistor so as to obtain desired characteristics, but is preferably 0.01 to 50,000 atomic ppm. More preferably, it is 0.5 to 10,000 atomic ppm, and preferably 0.5 to 5,000 atomic ppm.

In the present invention, I! The distribution of hydrogen atoms and/or electrically conductive substances in the functional thin film 4 is non-uniform in the film thickness direction. The content rate change may be such that the content rate gradually increases from the side of the substrate 2 to the surface side, or it may be such that the content rate decreases conversely. The change in the content of hydrogen atoms and/or the electrically conductive substance in the film thickness direction in the functional thin film 4 may be such as to have a maximum value or a minimum value in the thin H4. It is selected as appropriate to obtain desired characteristics depending on the intended use of the body.

2 to 7 show specific examples of changes in the content of hydrogen atoms and/or electrically conductive substances in the functional thin film 4 of the heating resistor of the present invention in the film thickness direction. The vertical axis represents the distance T in the film thickness direction from the interface with the base 2, and t represents the film thickness of the functional thin WJ4.
The horizontal axis represents the content C of hydrogen atoms and/or electrically conductive substances. In each figure, the scales of the vertical axis T and the horizontal axis C are not necessarily uniform, but vary to bring out the characteristics of each figure. I'm being forced to do it. Therefore, in actual application, various distributions are used for each diagram based on the differences in specific numerical values.

In the heating resistor of the present invention, an amorphous material (hereinafter referred to as
ra-C: Sometimes abbreviated as H(p,n)J. The functional thin film 4 consisting of (p, n) here represents an electrically conductive dominant substance is formed by, for example, a plasma CVD method such as a glow discharge method, or a vacuum deposition method such as a sputtering method.

For example, by glow discharge method a-C:H(p,n)
Basically, the substrate 2 is placed in a deposition chamber under reduced pressure, and carbon atoms (C) are
A raw material gas for supplying C that can supply hydrogen atoms (H), a raw material gas for supplying H that can supply hydrogen atoms (H), and a raw material gas for supplying an electrically conductive substance are introduced. /or A glow discharge is generated in the deposition chamber using high frequency or microwave while changing the amount of introduced raw material gas for supplying an electrically conductive substance, and a-c is generated on the surface of the substrate 2.
:H(p,n) may be formed.

In addition, a-C:H(p,n) can be obtained by sputtering method.
In order to form a thin film 4 consisting of
When sputtering a target composed of C in an atmosphere of an inert gas such as , He, or a mixed gas based on these gases, a raw material gas for supplying H and a raw material for supplying an electrically conductive substance are added to the deposition chamber. The gas may be introduced and the amount introduced may be changed at this time.

In the above method, as the raw material gas for supplying C, the raw material gas for supplying H, and the raw material gas for supplying electrically conductive substance, in addition to those in a gas state at room temperature and normal pressure, substances that can be gasified under reduced pressure may be used. I can do it.

Examples of raw materials for C supply include saturated hydrocarbons having 1 to 5 carbon atoms, ethylene hydrocarbons having 2 to 5 carbon atoms, acetylenic hydrocarbons having 2 to 4 carbon atoms, aromatic hydrocarbons, etc. The saturated hydrocarbons include methane (CH4), ethane (C2He), propylene (C:+HB), n-buta7 (n-C4HIO), pentane (05B12),
Ethylene hydrocarbons include ethylene (C2H4),
Propylene (C3Hs), butene-1 (C4H8)
, butene-2 (C4H8), inbutylene (C4
H8).

Pentene (05HIO), acetylene hydrocarbons include acetylene (C2H2), methylacetylene (C
Examples of aromatic hydrocarbons include benzene (C6He) and the like.

As a raw material for H supply, for example, hydrogen gas.

and hydrocarbons such as saturated hydrocarbons, ethylene hydrocarbons, acetylene hydrocarbons, and aromatic hydrocarbons, which are also the raw materials for supplying the above C.

Examples of raw materials for supplying electrically conductive substances include the following.

As a raw material for supplying group (III) atoms, for example, 82 He, B4) (to, B5 B9) for supplying boron atoms.
, E5H11, B6H10, B8H12, B6H14, etc., BF3, BC13, BB r3, etc. (
7)/'Boron halogenide, etc. are used, and AlCl3, GaCl3. Ga (CH3
)3. InCl3. TlCl3 etc. are used.

Examples of raw materials for supplying Group V atoms include hydrogenated phosphorus such as PH3 and P284, PH4I, and PF for supplying phosphorus atoms.
3, PFs, PC13, PC15, PBr3, P
Br3, PI3, etc. (7) Phosphorus halides, etc. are used, and AsH3, AsF3, A
sCl3. AsBr3, AsF5, SbH3, Sb
F3, SbF5.5bC13, 5bC15, BiI3
, BiCl3.

B i B r3 etc. are used.

These raw materials may be used alone or in combination.

In the above thin film forming method, in order to control the amount of hydrogen atoms and the amount of electrically conductive substances contained in the thin film 4 to be formed, as well as the characteristics of the thin film 4, it is necessary to control the substrate temperature, the supply amount of source gas, The discharge power, the pressure inside the deposition chamber, etc. are set appropriately.

In particular, in order to obtain the functional thin film 4 in which the distribution of hydrogen atoms and/or electrically conductive substances is non-uniform in the film thickness direction of the present invention, it is necessary to introduce hydrogen atoms and/or electrically conductive substances into the deposition chamber. Preferably, the amount is varied over time, for example by valve control.

The substrate temperature is preferably selected from 20-1500°C, more preferably 3ON1200°C, optimally 50-1ioo°C.

The supply amount of raw material gas depends on the desired thin film performance and the target t.
& It is determined as appropriate depending on the film speed.

Discharge power is preferably 0.001 to 20W/crn'
, more preferably 0.01-15 W/am'', optimally 0.05-IOW/ctn'.

The pressure in the deposition chamber is preferably between 10-4 and 1OT or
r, preferably lO-2 to 5Torrcy).

The thin film of the heating resistor of the present invention obtained using the above-described thin film forming method has properties close to those of diamond. That is, for example, Vickers hardness 1800-5000, thermal conductivity 0
．． 3~2cal/Cwesec*”0, resistivity 10-3
It has a property of ~106 Ω·Cm, and contains hydrogen atoms and an electrically conductive controlling substance, so it has extremely good resistance value controllability.

Of course, a layer having appropriate protection and other functions may be provided on the functional node g4 of the resistor of the present invention.

In the above explanation, the base body 2 is assumed to be a single body, but the base body 2 in the present invention may be a composite body. The configuration of one such embodiment is shown in FIG. show,
That is, the base 2 is composed of a composite body of a base 2a and a surface layer 2b, and the base 2a can be made of the base material described above with reference to FIG. 1, and the surface layer 2b can be formed on the base material. The surface layer 2b, which can use a material with better adhesion to the functional thin film 4, is made of, for example, an amorphous material having carbon atoms as a host, a conventionally known oxide, or the like. Such a surface layer 2b can be obtained by depositing an appropriate raw material on the base 2a by a method similar to the thin film forming method described above. Also, surface 1! J2b may be a normal glassy glaze layer.

Next, the outline of the manufacturing method of the heating resistor of the present invention will be explained.

FIG. 9 is a diagram showing an example of an apparatus used when forming a functional thin film on the surface of a substrate. 1101 is a deposition chamber, 1102-t106 is a gas cylinder IJ, 1107
~1111 is a mass flow controller, 1112
~1116 are inflow valves, 11L7~1121 are outflow valves, 1122~1126 are gas cylinder valves, 1127~1131 are outlet pressure gauges, 1132 is an auxiliary valve, 1133 is a lever,
, 1134 is the main valve, 1135 is the leak valve, 1.136 is the vacuum gauge, and 113
7 is a base material of the resistor to be manufactured, 1138 is a heater, 1139 is a base support, 1140 is a high voltage power supply, 1141 is an electrode, and 1142 is a shutter. Note that 1142-1 is a target attached to the electrode 1141 when performing the sputtering method.

For example, 1102 is sealed with CH4 gas (purity of 99.9% or more) diluted with Ar gas, and 1103
PH3 gas diluted with Ar gas (99.9% purity)
1104 is sealed with 82 H gas (purity of 99.9% or more) diluted with Ar gas. Before the gas in these cylinders flows into the deposition chamber 1101, each gas cylinder 1102 to 1106 (
7) Valves 1122 to 1126 and leak valve 113
5 is closed, and inlet valve 11 is closed.
12 to 1116, check that the outflow valves 1117 to 1121 and the auxiliary valve 1132 are open, and first open the main valve 1134 to evacuate the deposition chamber 1101 and gas piping. Approximately 1.
When the temperature reaches 5X10-6 Torr, auxiliary valve 11
32, inflow valves 1112 to 1116 and outflow valve 1
Close 117-1121. Thereafter, the valve of the gas pipe connected to the cylinder of the gas to be introduced into the deposition chamber 1101 is opened to introduce the desired gas into the deposition chamber ttoi.

Next, an example of a procedure for manufacturing a resistor of the present invention by a glow discharge method using the above-described apparatus will be described.

Open the valve 1122 and release CH4 from the gas cylinder 1102.
/Ar gas flows out, and valve 1123 is opened to flow out PH3/Ar gas from gas pump 1103, and the pressure of outlet pressure gauges 1127 and 1128 is set to l kg g/c.
then gradually open the inlet valves 1112, 1113 to allow flow into the mass flow controllers 1107, 1108, then the outlet valves 1117, tt.
ia, gradually open the auxiliary valve 1132 and turn on CH4/A.
r gas and PH3/Ar gas are introduced into the deposition chamber 1101. At this time, the flow rate of CH4/Ar gas and PH37A
The mass flow controllers 1107 and 1108 are adjusted so that the ratio with the flow rate of r gas becomes the desired value, and the
II! While checking the reading of the vacuum gauge 1136, adjust the opening degree of the main valve 1134 so that the pressure inside the valve 101 reaches the desired value! !
! do.

Then, the temperature of the base 1137 supported by the support 1139 in the deposition chamber 1101 is heated by the heater 1138 to a desired temperature, and then the shutter 1142 is heated.
is opened to generate glow discharge within the deposition chamber 1101.

Then, the flow rate of CH4/Ar gas and/or the flow rate of PH3/Ar gas is changed over time according to a pre-designed rate of change curve by operating to change the opening degree of the outflow valves 1117 and 1118 manually or by an external drive motor, etc. As a result, the content of H atoms or electrically conductive substances in the functional thin film 4 is changed in the film thickness direction.

Next, an example of a procedure for manufacturing the resistor of the present invention by sputtering using two or more devices will be described. Electrode 1 to which high voltage is applied by high voltage power supply 1140
High-purity graphite 1142-1 is placed as a target on 141 in advance, and in the same manner as in the glow discharge method, CH4/Ar gas is supplied from gas pump 1102 and PH3/Ar gas is supplied from gas pump 1103 at desired flow rates. and introduced into the deposition chamber 1101.

The target 1142-1 is sputtered by opening the shutter 1142 and turning on the high voltage power supply 1140. At this time, the substrate 1137 is heated to a desired temperature by the heater 1138, and the pressure inside the deposition chamber 1101 is set to a desired pressure by adjusting the opening degree of the main valve 1134, as in the case of the glow discharge method. Then, as in the case of the glow discharge method described above, the outflow valve 1117.11
18 is performed to change the flow rate of CH4/Ar gas and/or the flow rate of PH3/Ar gas over time according to a pre-designed rate of change curve, thereby reducing H atoms in the functional thin film 4. and/or changing the content of the electrically conductive substance in the film thickness direction.

Specific examples of the heating resistor of the present invention are shown below.

Example 1: An alumina ceramic plate was used as a substrate, and a heat generating resistance layer, which was a functional thin film, was formed on the surface of the substrate. The heating resistor layer was deposited by a glow discharge method using the apparatus shown in FIG. As raw material gas, cH4/A, r=
0, 5 (capacity ratio) and PH3/AAr-1000
pp (capacity ratio) was used. The conditions during the deposition were as shown in Table 1. still.

During deposition, the opening degree of the pulp is continuously changed to
A heat generating resistor layer having a thickness shown in Table 1 was formed by varying the flow rate of H4/Ar gas.

After forming an A1 layer on the formed resistance layer by electron beam evaporation, the A1 layer is formed by photolithography.
The layer was etched into the desired shape to form multiple pairs of electrodes.

Subsequently, predetermined portions of the resistive layer were removed by photolithography using an HF-based etching solution. still,
In this example, the size of the resistance layer between the electrode pairs is 100mm x 100p.In this example, the resistance layer formed between the electrode pairs has a pitch of 8/
A plurality of heat generating resistive elements were fabricated on the same substrate so as to be arranged in mm. In FIG. 10 which shows a partial cross-sectional view of the heating resistor element thus produced, 2 is a base, 4 is a heating resistor layer, and 6.7 is a pair of electrodes.

The electrical resistance of each heating resistor element thus obtained was measured and found to be 80Ω.

Furthermore, an electrical pulse signal was input to the heating resistor element obtained in this example to measure the durability of the heating resistor element. In addition, the duty of the electrical pulse signal is 50%,
Applied voltage 20V, drive frequency 90.5kHz, 1.0kHz
z, 2.0kHz.

As a result, in all cases of driving at different driving frequencies, the heating resistor element was not destroyed even when the electrical pulse signal input reached 1×10 10 times, and its resistance value hardly changed.

Example 2: Raw material gases were CH4/Ar gas, 5 (capacity ratio) and B2
In the same manner as in Example 1 except that H6/Ar=1000 ppm (capacity ratio), l? A heat generating resistor layer with a thickness of 1 inch was deposited.

Next, when a heating resistor element was prepared in the same manner as in Example 1 and an electrical pulse signal was input, the heating resistor element was not destroyed even when the electrical pulse signal input reached 1XloIO times. Further, no change in resistance value was observed.

Example 3: A heat generating resistor layer was deposited in the same manner as in Example 1 except that the CH,/Ar gas flow rate was kept constant and the discharge power was continuously varied to produce a heat generating resistor element.

When the heating resistor element thus obtained was driven in the same manner as in Example 1, it was confirmed that it had sufficient durability as in Example 1.

Example 4: A heat generating resistor layer was deposited to produce a heat generating resistor element in the same manner as in Example 2, except that the CH4/Ar gas flow rate was kept constant and the discharge power was continuously varied.

When the heating resistor element thus obtained was driven in the same manner as in Example 2, it was confirmed that it had sufficient durability as in Example 2.

[Effects of the Invention] According to the present invention as described above, thermal response is improved by using an amorphous material made of carbon atoms as a matrix and containing hydrogen atoms and an electrically conductive substance as a monofunctional thin film. The present invention provides a heat generating resistor having extremely good properties, thermal conductivity, heat resistance and/or durability, as well as resistance value controllability.

Furthermore, according to the present invention, the content of hydrogen atoms and/or electrically conductive substances in the monofunctional thin film is distributed non-uniformly in the film thickness direction, which improves heat storage and heat dissipation properties and the relationship between the substrate and the functional thin film. Various properties such as adhesion can be easily achieved.

[Brief explanation of the drawing]

1 and 8 are partial cross-sectional views of the heating resistor of the present invention. 2 to 7 are graphs showing the distribution of the content of hydrogen atoms and/or electrically conductive substances in the functional thin film. FIG. 9 is a diagram showing an apparatus used for manufacturing the heating resistor of the present invention. FIG. 10 is a partial cross-sectional view of a heating resistor element manufactured in an example of the present invention. 2: Substrate 4: Functional thin film 6.7: Electrode 1101: Deposition chamber 1137: Substrate Agent Patent attorney Seki Yamashita Child 1 Figure 8 Figure 1O Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (6)

[Claims] (1) A functional thin film made of an amorphous material having carbon atoms as a matrix and containing hydrogen atoms and a substance controlling electrical conductivity is formed on a substrate, and in the functional thin film, hydrogen atoms and/or Or a heating resistor characterized by a substance that controls electrical conductivity being distributed non-uniformly in the film thickness direction. (2) Hydrogen atom content in the functional thin film is 0.000
The heating resistor according to claim 1, wherein the heating resistor has a content of 1 to 30 atom %. (3) The heating resistor according to claim 1, wherein the functional thin film contains a substance that controls electrical conductivity in a range of 0.01 to 50,000 atomic ppm. (4) The substance that governs electrical conductivity is the element III of the periodic table.
The heating resistor according to claim 1, which is an atom belonging to the group A. (5) The heating resistor according to claim 1, wherein the substance that controls electrical conductivity is an atom belonging to Group V of the Periodic Table of Elements. (6) The heating resistor according to claim 1, wherein the base has a surface layer made of an amorphous material containing carbon atoms as a matrix on the side on which the functional thin film is formed.