JPH0992508A - Thin film thermistor forming method and manufacture of thin film thermistor element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily control the characteristics of a thin film thermistor element by a method wherein the specific resistance and the relative dielectric constant of a thin film thermistor are adjusted by regulating the mixing ratio of the mixture of O2 as the discharge gas to be introduced into a sputtering device. SOLUTION: When a thin film thermistor is provided by forming a thin film by a sputtering device using a metal composite oxide on a target, O2 -mixed gas is used as a discharge gas, and the specific resistance and the relative dielectric constant of the thin film thermistor are adjusted by regulating the mixing ratio of the mixed gas. As the metal composite oxide, an Mn-Co composite oxide, or Mn and Co are used as the main composition, and the composite oxide, etc., in which Ni, Ca, Cu, etc., are added, is used. A thin film thermistor element is formed on the electrode layer 2 formed on a substrate 1 on the thin film thermistor 4 formed on the electrode layer 2, and on the thin film thermistor 4, and an electrode layer 3, opposing to the electrode 2 with the thin film thermistor therebetween, is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a thin film thermistor whose specific resistance and relative permittivity are adjusted, and a method of manufacturing a chip type thin film thermistor element used for temperature compensation of a crystal oscillator.

[0002]

2. Description of the Related Art A small-sized communication device such as a mobile phone used outdoors is a temperature-compensated type including an AT-cut crystal oscillator, an amplifier and a temperature compensating circuit so that the change of the oscillation frequency due to the operating temperature is slight. Although the crystal oscillator of
As this temperature compensation circuit, the one shown in FIG. 5 is conventionally known.

This temperature compensation circuit, as shown in FIG.
A low temperature compensation circuit L and a high temperature compensation circuit H connected in series to the crystal unit are provided. The low temperature compensation circuit L has a capacitor C _L and a thermistor Th _L connected in parallel with each other, and the high temperature compensation circuit H has a capacitor C _H and a thermistor Th _H connected in parallel with each other. Both of the thermistors Th _L and Th _H have negative temperature characteristics. The amount of change in the ratio of the capacitances of the capacitors C _L and C _H to the equivalent series capacitance of the temperature compensation circuit as a whole with respect to temperature changes is small in the low temperature compensation circuit L at room temperature (25 ° C.) or higher, but at low temperatures. The capacitors C _L and C _H and the thermistors Th _L and Th _H are set so as to become large in the high temperature part and in the high temperature part compensating circuit H so as to become small in the high temperature part although it is small at room temperature and below. .

In order to adjust the compensation sensitivity of the temperature compensating circuit, a resistor R _L is inserted in parallel with the thermistor Th _L in the low temperature compensating circuit L, and a resistor R is connected in series with the thermistor Th _H in the high temperature compensating circuit 2. Inserting _H. Therefore, the chip type elements used in the low temperature part compensation circuit L and the high temperature part compensation circuit H require three types of thermistors, capacitors and adjusting resistors.

However, with the recent demand for miniaturization of crystal oscillators, it is required that the number of mounted components be smaller and that the manufacturing be easier.

Therefore, as a chip type thin film thermistor element useful as a thermistor for compensating for a low temperature portion of a temperature compensating circuit of a crystal oscillator, a base material and a first thin film thermistor formed on the base material are provided.
Thin film thermistor element having an electrode layer, a thin film thermistor formed on the first electrode layer, and a second electrode layer formed on the thin film thermistor and facing the first electrode layer with the thin film thermistor interposed therebetween. Is proposed. According to this, the thermistor element has the functions of the capacitor C _L of the low temperature compensation circuit and the adjusting resistor R _L in the conventional example of FIG. 4, and as shown in FIG. It is also possible to configure only Th _L ′.

[0007]

However, in order to configure the low temperature compensating circuit with only the thermistor element Th _L ′, the characteristics of the thermistor element having a negative temperature coefficient of resistance of 25 ° C. It is necessary to control the capacitance value between the first and second electrode layers at 5 to 25 MHz to be 15 pF or more and the resistance value to be 100Ω or less. When the capacitance value is less than 15 pF, the oscillation of the crystal oscillator becomes unstable, and when the resistance value exceeds 100Ω, the loss resistance becomes large, which is not desirable.

The characteristics can be controlled by adjusting the geometrical shape and dimensions of the element, such as changing the areas of the first and second electrodes and the thickness of the thin film thermistor. However, this method has a problem that when the geometrical shape or size is limited, the control of the characteristic is also limited accordingly, and the desired characteristic may not be obtained.

Therefore, an object of the present invention is to provide a freedom in characteristic control so that such characteristic control can be easily performed without changing the geometrical shape or size or in combination with the geometrical shape or size change. It is to provide a method of manufacturing a thin film thermistor element having high frequency.

[0010]

To achieve this object, according to the present invention, when a thin film thermistor is formed by depositing a thin film by a sputter rig apparatus using a metal composite oxide as a target, an electric discharge introduced into the sputter rig apparatus. A mixed gas of O ₂ is used as a gas, and the mixing ratio thereof is adjusted to adjust the specific resistance and relative permittivity of the thin film thermistor to be formed.
The thin film thermistor element manufactured according to the present invention is manufactured by applying this thin film thermistor forming method.

That is, the thin film thermistor element manufactured according to the present invention comprises a base material (1), a first electrode layer (2, 21) formed on the base material, and a thin film formed on the first electrode layer. The thermistor (4) and the second electrode layer (3, 24) formed on the thin film thermistor and opposed to the first electrode layer with the thin film thermistor interposed therebetween are used for manufacturing the thin film thermistor element. Forms a thin film pattern to be the first electrode layer on the substrate (31) to be the base material, and forms a thin film pattern to be the thin film thermistor thereon according to the method for forming a thin film thermistor described above. A thin film pattern serving as the second electrode layer is formed on the thin film pattern serving as the thin film thermistor, and the thin film pattern of the first electrode layer, the thin film thermistor, and the second electrode layer Formed by cutting the substrate so that the tip (34) of each of the thin film thermistor element.

Here, as the metal complex oxide, for example, a complex oxide of Mn and Co, or a complex oxide containing Mn and Co as main components and adding Ni, Ca, Cu, etc. is used. be able to.

[0013]

In this structure, for example, the discharge gas A
_{When r} is used and O ₂ is mixed with this to form a thin film thermistor, the relationship between the specific resistance ρ and the relative permittivity ε _{r of the} thin film thermistor to be formed and the volume ratio of O ₂ with respect to Ar is shown in the respective figures. 1 (a) and (b). FIG. 1 (a) is based on the value calculated from the DC resistance value at 25 ° C., and FIG.
This is based on the value calculated from the capacitance value (Cp) at 5 MHz. Mn, Co and Mn, Co, respectively
It shows about the Ni composite oxide. Therefore, by adjusting the proportion of O ₂ based on such a relationship, a thin film thermistor having a specific resistance and a relative dielectric constant corresponding to the proportion is formed, and the resistance value and the capacitance value of the thin film thermistor element are controlled. It The formed thin film thermistor is preferably annealed in order to reduce the change with time.

Thus, for example, in the case of the NTC type thin film thermistor element for compensating for the low temperature part in the temperature compensating circuit of the crystal oscillator, as described above, the temperature is 25 ° C. and the temperature is 5 to 25 MH.
z has a capacitance value of 15 pF or more and a resistance value of 10
It is controlled to be 0Ω or less. Further, in the case of compensation for a high temperature part, the capacitance value of the element at 25 ° C. and 5 to 25 MHz is controlled to be 15 pF or more and the resistance value is 2 kΩ or more. The thin film thermistor element whose characteristics are controlled as described above can satisfy the characteristics required for a circuit for low temperature compensation or high temperature compensation with only the element.

[0015]

2 is a perspective view showing the structure of a thermistor element manufactured by a manufacturing method according to an embodiment of the present invention. As shown in the figure, this device includes a base material 1, a lower electrode 2 and an upper electrode 3 provided on the base material 1, and a lower electrode 2.
Thin film 4 provided between the upper electrode 3 and the upper electrode 3, an insulating protective layer 5 formed on the upper electrode 3, an adhesion layer 6 provided on both end surfaces of the base material 1, an electrode applied to the outer surface of the adhesion layer 6. It has a layer 7 and a solder layer 8 covering the electrode layer. The lower electrode 2 and the upper electrode 3 have an overlapping portion having a constant area with the thermistor thin film 4 interposed therebetween, and the both electrodes are not directly connected. The adhesion layer 6, the electrode layer 7, and the solder layer 8 constitute two end face electrodes, and the adhesion layer 6 of each end face electrode is connected to the lower electrode 2 and the upper electrode 3, respectively.

The substrate 1 is made of barium borosilicate glass or the like. The lower electrode 2 and the upper electrode 3 are thin films of nickel, chromium, aluminum, titanium, copper, or the like. The thermistor thin film 4 is a manganese-cobalt composite oxide, which is a composite oxide containing at least one of nickel, copper, and calcium.

The protective layer 5 is formed so that the thermistor thin film 4 is not exposed and the end face portion 2 of the upper electrode 3 and the lower electrode 2 is covered.
4 is provided so as to be exposed. Examples of the material of the protective layer 5 include insulating heat resistant resins such as silicone resin, epoxy resin, and polyimide resin. Also, the upper electrode 3
It is also possible to form a silicon oxide thin film on top of this, provide an insulating heat-resistant resin on it, and form the protective layer 5 with these layers to improve heat resistance.

The thermistor thin film 4 has a thickness of 0.5 to 20 μm.
When the thickness is less than 0.5 μm, it is difficult to control the capacitance value (Cp) and the resistance value (Rp) of the device, and when the thickness exceeds 20 μm, a thick film region is formed, resulting in high cost. The area (electrode area) of the overlapping portion of the upper electrode 3 or the lower electrode 2 is 100 to 800 μm in length × 100 in width.
６００600 μm. 25 if the electrode area is smaller than this
The capacitance value (Cp) at 15 ° C. and 15 MHz cannot satisfy the later-described requirement that the capacitance value (Cp) is 15 pF or more and is limited by the chip size.
However, by controlling the specific resistance and relative permittivity of the thermistor thin film 4 according to the present invention, such dimensional limitation is alleviated.

The adhesion layer 6 is made of a titanium or chromium thin film, and the electrode layer 7 is a nickel thin film, or copper, nickel,
It consists of a polymer or cermet thick film whose main component is silver. The surface layer 8 is composed of a solder underlayer such as a tin thin film or a layer of Pb / Sn, Ag / Sn or the like thereon. The end face electrodes formed by the adhesion layer 6, the electrode layer 7 and the surface layer 8 need to be formed so as to cover the exposed portions of the upper electrode 3 and the lower electrode 2. The adhesive layer 6 may be formed by applying a resin curable paste containing silver powder as a main component to both end faces and curing the paste.

This thermistor element has a negative temperature coefficient of resistance, and by utilizing the electric conduction characteristic and the dielectric characteristic of the thermistor, a low temperature compensation circuit is realized in one chip Th _L ′ as shown in FIG. To do. That is, by thinning the composite oxide forming the thermistor and adding the dielectric property, the capacitor C _L and the resistor R _L shown in FIG. 5 for compensating for the low temperature part are not necessary.
For that purpose, the capacitance value (Cp) at 25 ° C. and 5 to 25 MHz is 15 pF or more, and the resistance value (Rp) is 10 pF.
It must be 0Ω or less. Capacitance value (Cp) is 15pF
When it is less than 1, the oscillation of the crystal oscillator becomes unstable, and when the resistance value (Rp) exceeds 100Ω, the loss resistance becomes large, which is not desirable.

Next, an embodiment of the method for manufacturing the thermistor element will be described. The production is performed according to the following procedures (1) to (10).

(1) Substrate treatment: 100 m in length as the substrate 1
A barium borosilicate glass substrate having a size of m, a width of 100 mm and a thickness of 0.5 mm was prepared, degreased in an ultrasonic cleaning tank filled with a neutral detergent, and then washed with ultrapure water, and a clean room Dry in a room temperature at room temperature.

(2) Lower electrode film formation: A drum type sputtering apparatus as shown in FIG. 3 is used to form a pattern of the lower electrode 2 by a lift-off method. That is, first, a portion other than the portion where the lower electrode 2 pattern is formed on the substrate is covered with a resist, and this substrate is mounted on the rotary drum 11. next,
Titanium and nickel are sequentially used as the sputtering target 13, the rotary drum 11 is rotated, and sputtering is performed while supplying the argon gas flow 12.
After the sputtering is completed, the resist is peeled off. As a result, a pattern of the lower electrode 2 made of a nickel thin film having a film thickness of 0.3 μm is formed using a titanium layer having a film thickness of 0.1 μm as an adhesion layer to the substrate. Titanium was used as the adhesion layer because of its adhesion to the barium borosilicate glass that constitutes the substrate 1, and the thermistor thin film 4 (manganese / cobalt / cobalt
The effect on the nickel composite oxide thin film) is taken into consideration. The film forming conditions are as follows.

[Film forming conditions] Sputtering pressure: 5 mmTorr, Ar gas flow rate: 120 c
c / min. , DC power: 3 kW, titanium film formation time:
20 minutes, nickel film formation time: 30 minutes, drum rotation: 10
rpm.

(3) Thermistor film formation: A pattern of the thermistor thin film 4 is formed by a lift-off method using the drum type sputtering apparatus shown in FIG. That is, first, the substrate on which the pattern of the lower electrode 2 is formed is covered with a resist except the portion where the thermistor thin film 4 pattern is formed, and this is mounted on the rotary drum 11. Next, sputtering target 1 of manganese-cobalt-nickel composite oxide
3, the rotary drum 11 is rotated, and sputtering is performed while supplying the mixed gas flow 12 of argon and oxygen. Then, after the sputtering is completed, the resist is peeled off. As a result, a thermistor thin film (manganese / cobalt / nickel composite oxide thin film) pattern having a predetermined shape and a thickness of 1.0 μm is formed on the substrate and the lower electrode 2.
The film forming conditions are as follows.

[Film Forming Conditions] Sputtering pressure: ₂ mm Torr, mixed gas flow rate of Ar and O ₂ : 20 cc / min. (Ar: 18 cc / mi
n. , O ₂ : ₂ cc / min. ), DC power: 1K
W, film formation time: 8 hours, drum rotation: 10 rpm.

(4) Upper electrode film formation: The pattern of the upper electrode 3 is formed by the lift-off method using the drum type sputtering apparatus shown in FIG. That is, first, the substrate on which the pattern of the thermistor thin film 4 is formed is covered with a resist except the portion where the pattern of the upper electrode 3 is formed, and this substrate is mounted on the rotary drum 11. Next, using nickel as the sputtering target 13, the rotary drum 11 is rotated and sputtering is performed while supplying the argon gas flow 12. Then, after the sputtering is completed, the resist is peeled off. As a result, three patterns of the upper electrode (nickel thin film) having a thickness of 0.3 μm are formed. The film forming conditions are as follows.

[Film forming conditions] Sputtering pressure: 5 mmTorr, Ar gas flow rate: 120 c
c / min. , DC power: 3 kW, film formation time: 30
Min, drum rotation: 10 rpm.

(5) Deposition of protective film: Using the drum type sputtering apparatus shown in FIG. 3, a silicon oxide thin film forming the protective layer 5 is formed on the upper electrode 3 pattern by the lift-off method. That is, first, the portion of the protective layer 5 other than the portion where the pattern is formed is covered with a resist. At this time, the protective layer 5 is formed on the upper electrode 3 such that the thermistor thin film 4 is not exposed and the end face portions of the upper electrode 3 and the lower electrode 2 are exposed. The resist is arranged so that the pattern is formed as a continuous stripe pattern between adjacent elements in the Y direction. Next, using SiO ₂ as the target 13, the rotary drum 11 is rotated, and sputtering is performed while supplying the argon gas flow 12. Then, after the sputtering is completed, the resist is peeled off. As a result, a 0.4 μm thick silicon oxide thin film forming the protective layer 5 is formed. The film forming conditions are as follows.

[Film forming conditions] Sputtering pressure: 2 mmTorr, Ar gas flow rate: 20 cc
/ Min. , DC power: 1 kW, film formation time: 4 hours,
Drum rotation: 10 rpm.

(6) Annealing: 3 by air oven
Annealing is carried out at 00 ° C. for 4 hours, and then naturally cooled in air. By this annealing and mixing of O ₂ gas with Ar gas in the thermistor film forming step (3), the thermistor thin film 4 has improved thermal stability and reduced change over time.

(7) Protective resin printing: Using a patterned metal mask having a thickness of 0.1 mm, epoxy thermosetting resin was screen-printed by a screen printing machine, and this was printed in an exhaust type oven at 200 ° C. at 30 ° C. By heat-curing for a minute, an insulating heat-resistant resin layer having a thickness of 50 μm is formed on the silicon oxide thin film. As a result, the pattern of the protective layer 5 including the silicon oxide thin film and the insulating heat resistant resin layer is formed.

(8) Sticking: In the following description of the steps, FIG. 6 is referred to in particular. The substrate 31 on which the thin film pattern up to the protective layer 5 is formed is placed on the adhesive tape, and this is placed in a dicing device, and the substrate on the adhesive tape is made into a stick shape by the diamond blade rotating at a high speed. Cut off sequentially. The cross section of each stick corresponds to the cross section of one chip of the thermistor element shown in FIG. That is, the cutting direction is parallel to the YZ plane if the XYZ directions are defined as shown in FIGS. 2 and 6 with the thermistor element as a reference, and the cutting interval is the same as the width W _x of the substrate 1 in the X direction. Next, the base material 1 cut in this way is peeled off from the adhesive tape. This makes the length 1
A large number of stick-shaped objects 32 each having a size of 00 mm, a width of 0.8 mm, and a thickness of 0.5 mm are cut into sticks.

(9) Film forming of end face electrodes: A plurality of the stick-like objects 32 are aligned in the same direction, and the stick-like objects 32 are stacked in the Z direction. Next, the stack 33 is mounted on the rotary drum 11 of the sputtering apparatus of FIG. 3 so that the sputtering is performed from the positive X direction. Then, using titanium, nickel, and silver as sputtering targets in this order, the rotary drum 11 is rotated, and the tatami mat is sputtered in the positive X direction A. Further, sputtering is performed in the same manner from the opposite direction, that is, from the negative direction B of X. As a result, the thickness is 0.05μ
An end face electrode including an adhesion layer (titanium thin film) 6 having a thickness of m, an electrode layer (nickel thin film) 7 having a thickness of 0.5 μm, and a surface layer (silver thin film) 8 having a thickness of 0.2 μm is formed. Figure 6
(B) shows a state in which a part of the stack 33 after the completion of sputtering is enlarged and viewed from the Y direction. Since the pattern of the protective layer is formed as a continuous stripe pattern between the elements adjacent in the Y direction, as shown in FIG. 6B, the pattern 5s of the protective layer allows the end face electrodes on both sides to be formed. The thin film patterns 23 are formed separately from each other. The film forming conditions are as follows.

[Film forming conditions] Sputtering pressure: 5 mm Tor
r, Ar gas flow rate: 120 cc / min. , DC power: 3 kW, titanium film formation time: 10 minutes, nickel film formation time: 30 minutes, silver film formation time: 10 minutes, drum rotation: 10r
pm.

(10) Chip formation: The above-mentioned stacked product is separated by the dicing device in parallel with the XZ plane at 1.6 mm intervals W _y.
Disconnect with. As a result, the length (dimension in Y direction) of one chip is 1.6 mm, and the width (dimension in X direction) is about 0.8 mm.
Thermistor element 34 having a thickness (dimension in the Z direction) of 0.5 mm
Can be obtained multiple times.

The AC value of the thus obtained thermistor element was evaluated by the following method, and the result was evaluated for thermistor (manganese / cobalt complex oxide sintered body) and capacitor conventionally used for low temperature compensation. Table 1 with values
Shown in

[AC value] After the element was set on a measuring jig installed in a circulating-type constant temperature bath at 25 ° C and 0 ° C, the resistance value (Rp) and capacitance (Cp) of the element at 15 MHz were measured by an impedance analyzer. ) Is measured.

[0039]

[Table 1] The results of evaluating the temperature compensation characteristics of this thermistor element by the following method are also shown. First, FIG. 7 shows the temperature compensation characteristic of the temperature compensation circuit of the crystal oscillator shown in FIG. 5, which has a thermistor, a capacitor and a resistor in the conventional low temperature compensation circuit. FIG. 8 shows the temperature compensation characteristic of the temperature compensation circuit of the crystal oscillator using the above, and the temperature compensation characteristic of the temperature compensation circuit of the crystal oscillator shown in FIG. 4 using only the thermistor element of the present invention as the low temperature compensation circuit. Each is shown in FIG.

[Temperature Compensation Characteristic] A crystal oscillator in which a desired element was connected to a low temperature compensating circuit was installed in an air circulation type constant temperature bath capable of adjusting from −30 ° C. to + 80 ° C. A DC power source (5V) and a frequency counter are connected to the crystal oscillator, and the oscillation frequency is measured while changing the temperature.
When the oscillation frequency at 25 ° C. is f25, the frequency deviation value at T ° C. is expressed by the following equation. Δf / f = (fT−f25) / f25 As is clear from the comparison of FIGS. 7 to 9, the temperature compensation characteristic shown in FIG. 9 is almost the same as that of FIG. 7, and the temperature compensation characteristic shown in FIG. You can see that it has improved.

The thermistor (manganese-cobalt complex oxide sintered body) and capacitor conventionally used for compensating low temperature parts and the capacitance value (Cp) and resistance value (Rp) at 5 to 25 MHz were measured as follows. The results are shown in FIG. 10 under the conditions, and the capacitance value (Cp) and the resistance value (Rp) at 5 to 25 MHz of the thermistor element of this example were measured in the same manner, and the results are shown in FIG.

[Measurement conditions] The capacitance value (Cp) and the resistance value (Rp) were measured by an impedance analyzer installed in a room whose temperature was adjusted to 25 ° C.

FIG. 12 is a sectional view of a thermistor element manufactured by a manufacturing method according to another embodiment of the present invention. This element includes an intermediate electrode 21 provided on the base material 1, a thermistor thin film 4 provided from the intermediate electrode 21 to both ends of the base material 1 in the X direction, and one end portion to the other end portion in the X direction on the thermistor thin film 4. The intermediate electrode 21
Two side electrodes 22 separated in the middle of the
2 is provided with a protective layer 5 covering the both sides except the both end sides, and two end face electrodes 23 provided from the both end sides on each electrode 22 to each end face parallel to the YZ plane of the substrate 1. .

In this structure, the capacitance of the element is obtained by connecting the capacitances of the facing portions of the intermediate electrode 21 and the electrodes 22 in series. Therefore, in order to obtain the same characteristics as those of FIG. 2, the thermistor thin film 4 is made thinner than that of FIG. 2, and the O ₂ added to the discharge gas when the thermistor thin film 4 is formed is formed. This is dealt with by adjusting the amount and controlling the specific resistance and relative permittivity of the thermistor thin film 4.

This element is similar to the above-mentioned embodiment,
By forming a thin film, the electrodes 21 and 22, the thermistor thin film 4,
Although the protective layer 5 and the like are formed, since the thermistor thin film 4 is continuously formed from one end to the other end in the X direction,
The pattern of the thermistor thin film 4 formed on the substrate is X
The elements adjacent to each other in the direction are formed as a striped pattern continuous in the X direction or as a single thin film covering the entire surface of the substrate. Also, sticking, formation of end face electrodes, chipping, etc. are performed in the same manner as in the above-mentioned embodiment.

[0046]

As described above, according to the present invention,
A mixture of O ₂ is used as a discharge gas to be introduced into the sputter rig device, and the specific resistance and relative permittivity of the thin film thermistor to be formed are adjusted by adjusting the mixing ratio thereof. Can be easily controlled without changing the geometric shape or in combination with the change of the geometric shape.

[Brief description of drawings]

FIG. 1 is a diagram showing the relationship between the amount of O _{2 in} a discharge gas introduced into a sputtering apparatus and the specific resistance and relative permittivity of a thin film thermistor to be formed in order to explain the principle of the present invention.

FIG. 2 is a perspective view showing a structure of a thermistor element manufactured by a manufacturing method according to an embodiment of the present invention.

3A and 3B are a side view and a top view showing a drum type sputtering apparatus used in a manufacturing method according to an embodiment of the present invention.

FIG. 4 is a circuit diagram showing a temperature compensation circuit using a thermistor element manufactured by the manufacturing method of the present invention.

FIG. 5 is a circuit diagram showing a temperature compensation circuit according to a conventional example.

FIG. 6 is a diagram conceptually showing steps from sticking to chipping in the manufacturing method according to one embodiment of the present invention.

FIG. 7 is a graph showing temperature compensation characteristics of a temperature compensation circuit used in a conventional crystal oscillator.

FIG. 8 is a graph showing a temperature compensation characteristic when a low temperature part compensation circuit of a temperature compensation circuit used for a crystal oscillator is removed.

FIG. 9 is a graph showing temperature compensation characteristics of a temperature compensation circuit in which a thermistor element manufactured by a manufacturing method according to an embodiment of the present invention is used as a thermistor for compensating a low temperature portion of a temperature compensation circuit in a crystal oscillator.

FIG. 10 shows a thermistor (manganese-cobalt composite oxide sintered body) 5 which has been conventionally used for compensating for a low temperature part.
Capacitance value (Cp) and resistance value (Rp) at 25MHz
It is a graph which shows.

FIG. 11 is a graph showing the capacitance value (Cp) and the resistance value (Rp) at 5 to 25 MHz of the thermistor element manufactured by the manufacturing method according to the embodiment of the present invention.

FIG. 12 is a sectional view of a thermistor element manufactured by a manufacturing method according to another embodiment of the present invention.

[Explanation of symbols]

1: base material, 2: lower electrode, 3: upper electrode, 4: thermistor thin film, 5: protective film, 6: adhesion layer, 7: electrode layer, 8: surface layer, 11: rotating drum, 12: gas flow , 13: target, 21: intermediate electrode, 22: both side electrodes, 23: end face electrode, 24:31: substrate, 32: stick-like material, 33:
Stack, 34: Thermistor element.

Claims (5)

[Claims] 1. When forming a thin film thermistor by depositing a thin film with a sputter rig using a metal composite oxide as a target, a mixture of O ₂ is used as a discharge gas introduced into the sputter rig, and the mixing ratio thereof is used. A method for forming a thin film thermistor, comprising adjusting the specific resistance and relative permittivity of the thin film thermistor to be formed by adjusting the. 2. The metal complex oxide is Mn and Co.
2. The method for forming a thin film thermistor according to claim 1, wherein the thin film thermistor is a complex oxide of 1 or a metal complex oxide containing Mn and Co as main components. 3. The method for forming a thin film thermistor according to claim 1, wherein the thin film formed by the sputtering apparatus is annealed. 4. A base material (1), a first formed on the base material.
Electrode layer (2, 21), a thin film thermistor (4) formed on the first electrode layer, and a second thin film thermistor that is formed on the thin film thermistor and faces the first electrode layer with the thin film thermistor interposed therebetween. A method of manufacturing a thin film thermistor element having electrode layers (3, 22), comprising: forming a thin film pattern to be the first electrode layer on a substrate (31) to be the base material; A step of forming a thin film pattern to be the thin film thermistor on the thin film pattern to be one electrode layer by the method according to claim 1 or 2, and the second step to be formed on the thin film pattern to be the thin film thermistor.
A step of forming a thin film pattern to be an electrode layer, and cutting the substrate on which the thin film pattern of the first electrode layer, the thin film thermistor, and the second electrode layer is formed, and a chip (34) for each thin film thermistor element A method of manufacturing a thin film thermistor element, comprising: 5. The thin film according to claim 4, further comprising a step of forming thin film patterns of the first electrode layer, the thin film thermistor, and the second electrode layer, and then annealing the thin film patterns. Manufacturing method of thermistor element.