JPS6083301A - Thin film 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 The present invention relates to a thin film resistor used, for example, as a heating resistor of a thermal head, and particularly relates to a chromium-silicon oxide type or chromium-silicon-silicon oxide type (hereinafter collectively referred to as these). Chromium-Silicon-Oxygen thin film resistor.

In recent years, with the rapid development of electronic technology, the demands on the electrical characteristics of circuit elements have become increasingly strict, and it has become necessary to improve the performance of the elements themselves.

Conventionally, tantalum nitride, tantalum-silicon, and the like have been used as heating resistors for thermal heads. However, these materials have disadvantages in that oxidation progresses due to repeated heat generation, resulting in a large change in resistance value and deterioration of printing quality.

In order to overcome this drawback, a chromium-silicon MCr, 1° thread thin film resistor was proposed, and although it was able to stabilize the characteristics to some extent under high temperatures, If left as is, a change in resistance value will appear, which is not completely satisfactory.

The present inventors conducted various investigations into the resistance value change of chromium-silicon f-based thin film resistors at high temperatures.
It was revealed that there is a correlation between the silicon content in the product composition and the change in resistance at 1% IIA.

In other words, Figure 1 is a characteristic diagram showing the UtJ relationship between the silicon content in a chromium-silicon-oxygen thin film resistor and the rate of change in resistance value (ΔR/R) under high i% (xzs°C). be. Each sample had a combined target structure in which a chromium plate was placed on silicon having a diameter of 1271 ψ as a target, and a film was formed using an RF magnetron sputtering device.

The composition ratio (silicon content) of the resistor to be formed was adjusted by changing the area occupation rate of the chromium plate on target 7.

Each sample was prepared by sputtering at a speed of U5o for 17 minutes.

In Figure 1, curve A shows a silicon content of 68 atoms.
Curve B has the same content of 66 atoms. Curve C has the same content of 4 atoms.
A curve of 5 atoms and 1 curve is a resistor with a content of 30 atoms. As is clear from this figure, when curves A and B have a high silicon content like those previously proposed, if they are left continuously at high temperatures for a long time, the rate of change in resistance gradually increases. Silicon content is over 68 atoms (curve A
) Then, if you leave it at 125℃ for 1000 cycles, the rate of change in resistance value will reach 0.8cm. Adding λj to this, the silicon field content in the resistor is 45 atoms or less (curve C
, D) has an extremely small resistance value change rate even in high-temperature tests, and the resistance value change rate is extremely small even when left at 125°C for 1000 hours in the case of 45% hydrogen (curve C). is about 0.12%, which is about one-sixth or less of the silicon content of 68 atoms mentioned in item 11. In addition, for the silicon-free material (curve D) with a silicon content of over 30 atoms, the rate of change in resistance value is almost zero even if it is repeatedly heated for a long time at high temperature. There is almost no change in resistance value.

As is clear from these results, chrono-silicon-
G (US-based thin resistor 14, medium & 1z) By regulating the silicon content to about 45 atoms or less, the performance has a small resistance change rate even when left at X'jl temperature for a long time. As mentioned above, as the silicon content in the thin film resistor decreases, the rate of change in resistance value tends to decrease. When d.1 is exceeded, patterning using an etching agent (nitric acid and hydrogen fluoride) becomes difficult, resulting in problems in workability and processing accuracy. Therefore, it is better to keep the lower limit of the silicon content at about 20 atoms, and in particular, when the silicon content is about 20 to 40 atoms, the rate of change in resistance J/C value is extremely small and etching becomes difficult. Let's do it without hesitation
reactor.

In addition, as a result of studying the oxygen partial pressure when creating a chromium-silicon-oxygen-based resistor with a SiF content of about 45 atoms or less, it was found that about 1 x 10 to 2 x 10'rorr is suitable. It was found that when the partial pressure of oxygen becomes too large, the temperature coefficient of resistance T, O, R, increases to the negative side.
10 T or rze, (the power that is kept at a certain degree is good.

Further, when the chrono-silicon-oxygen resistor according to the present invention is heat-treated in a temperature range of about 250 to 350° C. after being formed into a chrono-silicon-oxygen resistor, a resistor with even lower performance can be obtained. In other words, if the heat treatment is performed within the humidity range mentioned above, even silicon content near the upper limit (approximately 45 atoms) can be heated to a high 1fa.
It is not possible to further suppress the rate of change in the L value by moving it downward (-). In addition, Elk place (jl! temperature is 250
If it is lower than ℃, it will be sufficient to obtain the effect of LC〆〆2~〆1・J〆〆4'
On the other hand, if the heat treatment temperature exceeds 350°C, crystallization of chrono-silicon will begin, which will have a negative impact on stabilizing performance, which is not preferable.

Furthermore, a thin III''1.
Form the antibody Φ1 on a high-temperature substrate, then OI
As mentioned above, a method of heat treatment at approximately 250 to 350°C is used, and depending on the heat treatment time, the
can be added in the range of about 30 to 50 ppm/°C, so the resistance nl immersion coefficient can be adjusted to some extent or 0 (te).

Next, examples of the present invention will be described.

Using an RF magnetron sputtering device 17r with a cross and a plate placed on a silicon target of 127 RNψ, 99.5 il j
J heated to 300℃ containing alumina of 4"
, without sputtering silicon and chromium on one plate 1).

The oxygen partial pressure at the time of desertion was 5.3 x 10 TOrr, which is 1. Ina 1. Sputtering is performed at a +(l-wave tIL power of 250 W sm and a speed of 50 λ/min) to form a chrome-oxide-oxygen thin film resistor having a silicon content of approximately 40 atoms.

Next, using an etching agent consisting of nitrogen Q and hydrogen fluoride, t,? The primary thin film resistor is patterned into a predetermined shape to form dotted resistance heating parts 2cL to 2g. Thereafter, individual T [corresponding to each of the resistor heating parts 2a to 22] are formed using the vaporization method or the sputtering method to form the electrodes 3α to 32 and the common electrode 4 according to a conventional method, and then heat treated in the atmosphere at 300° C. for 2 hours. and remove the thermal head.

The present invention has a till structure as described above, and has a high + i
! It is possible to provide a stable thin film resistor with a low resistance value conversion rate even if it is exposed to heat for a long time under the condition 6).

[Brief explanation of drawings]

FIG. 1 is a characteristic diagram showing the relationship between silicon content and resistance change rate, and FIG. 2 is a plan view of a thermal head according to an embodiment of the present invention. 1...Substrate, 2a to 27...1. lL
Anti-care t-trien. Procedural amendment (voluntary) June 3, 1980 Kazuo Wakasugi, Director General of the Patent Office ■ Indication of the case Patent Application No. 1989-190914 2 Name of the invention Thin film resistor 3 Person making the amendment Related Applicant Address 1-7 Yukitani Otsuka-cho, Ota-ku, Tokyo Name (A
O9) Alps Electric Co., Ltd. Representative Kataoka Kataoka 4 Agent address 1-6-13-6 Nishi-Shinbashi, Minato-ku, Tokyo 105
The details of the amendment are as stated in the attached sheet. (1) Please correct page 7, lines 7 to 14 of the detailed statement as follows. ``Next, an electrode film is formed by vapor deposition or sputtering, and after patterning the individual electrodes 3a to 3g and the common electrode 4 into a predetermined shape using an etching agent, the thin film resistor is patterned to form a dot-shaped resistance heating section. 28 to 2 g is formed.Then, heat treatment is performed at 300° C. for 2 hours in the atmosphere to form a thermal head.”

Claims (2)

[Claims] (1) A chromium-silicon-oxygen-based thin film resistor, characterized in that the silicon content is about 45 atoms or less. (2) A thin film resistor according to claim (1), wherein the silicon content is regulated to a range of about 26 to 40 atoms.