JPS62202759A - Production of exothermic resistance element - Google Patents

Abstract

PURPOSE:To enable accomplishment of an electric power saving, a high durability, and a high-speed responsiveness to heat, by a method wherein, after the lamination of an upper layer on a thermal energy generating means, an etching is applied to the upper layer to form a protective layer. CONSTITUTION:An exothermic resistance element consists of; a substrate 1, an exothermic resistance layer 2 formed thereon, a thermal energy generating means consisting of at least one pair of electrodes 3, 4 electrically connecting to the layer 2, and a protective layer 5 obtained by a method in which an upper layer to be a protective layer 5 is formed on the means followed by an etching of the upper layer. In this manner, the protective layer 5 can be obtained by the repetition of the lamination and the etching of the upper layer, thus enabling elimination of a nonuniform film quality, etc. causing occurrence of a pinhole or crack as well as the enhancement of a step coverage. Therefore, the exothermic resistance element capable of an electric power saving together with a high durability and a high-speed responsiveness to heat can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for producing a heat generating resistor element, and particularly to a method for producing a heat generating resistor element having a protective layer.

[Conventional technology]

Conventionally, various recording methods using thermal energy, such as a thermal transfer recording method, have been known. A heating resistance element used in such a recording method using thermal energy generally includes a heating resistance layer and at least a pair of heating resistance elements electrically connected to the heating resistance layer and arranged to heat the heating resistance layer with electricity. It has a thermal energy generating means consisting of an electrode. In addition, such a heat generating resistor element is usually provided with a protective layer for the purpose of preventing oxidation of the heat generating resistor layer and preventing short circuit between electrodes. After the layers are formed on the desired substrate, electrodes and protective layers are typically laminated in sequence.

The protective layer of such a heat-generating resistor element is designed to fully fulfill various functions as a protective layer, such as preventing oxidation of the heat-generating resistor layer and preventing short circuits between electrodes. It is required to uniformly cover the required portions of the material without layer defects such as pinholes.

By the way, as mentioned above, in such a heat generating resistor element, since the electrode is generally formed on the heat generating resistor layer F, a step occurs between the electrode and the heat generating resistor layer. Since non-uniformity in layer thickness is likely to occur, the layer must be formed in such a way as to sufficiently cover the step without leaving exposed portions (step force deflection). That is, in a state where step coverage is insufficient, oxidation gradually progresses from the exposed portion of the heat generating resistor layer, and depending on the degree, it may lead to destruction of the heat generating resistor element. In addition, non-uniformity in film quality is likely to occur at such stepped portions, and such non-uniformity in film quality leads to local concentration of thermal stress generated in the protective layer due to repeated heat generation, causing cracks in the protective layer. This may also cause cracks to occur, and oxidation may proceed from these cracks, leading to destruction of the heating resistor layer. Furthermore, oxidation progressed through the pinholes, leading to destruction of the heating resistor layer.

Conventionally, in order to solve such problems, the general practice has been to increase the thickness of the protective layer to improve step coverage and reduce pinholes. However, although increasing the thickness of the protective layer contributes to reducing step coverage and pinholes, increasing the thickness of the protective layer impedes heat supply to the outside of the element, causing new problems such as the following. became.

In other words, the heat generated in the heat generating resistor layer is transferred to the outside of the element through the protective layer, but the thermal resistance between the surface of the protective layer, which is the surface on which this heat acts, and the heat generating resistor layer is Increasing the layer thickness increases the size, which makes it necessary to apply more power load than necessary to the heat-generating resistor layer, which is disadvantageous to power saving, and which causes more heat than necessary to accumulate in the base, resulting in poor thermal response. (2) The durability of the heat generating resistor layer deteriorates due to more power than necessary.

Such problems can be overcome by making the protective layer thinner, but conventional methods for forming heat generating resistor elements using film forming methods such as sputtering or vapor deposition suffer from poor step coverage, etc., as described above. There were drawbacks in terms of durability, and it was difficult to make the protective layer thin.

[Problem that the invention seeks to solve]

The present invention has been made in view of the problems of the conventional examples described above, and its main purpose is to provide a method for producing a novel heating resistor element that can achieve power saving, high durability, and high-speed thermal response. purpose.

[Means for solving problems]

The present invention achieves the above objects by forming on a base at least one or more sets of thermal energy generating means each consisting of a heat generating resistive layer and at least one pair of electrodes electrically connected to the heat generating resistive layer; A method for producing a heat generating resistor element comprising laminating an upper layer serving as a protective layer on the means, the method comprising etching the upper layer after the upper layer hI layer. .

Hereinafter, the present invention will be described in detail with reference to the drawings as necessary.

FIG. 1 is a partial plan view of an example of a heating resistor element obtained by applying the method of the present invention, and FIG. 2 is an X-Y sectional view thereof.

As illustrated in FIGS. 1 and 2, a heating resistor element to which the present invention is applied includes a heating resistor layer 2 and at least one pair of electrodes 3 electrically connected to the layer 2 on a desired base 1.
．． 4, and a protective layer 5 obtained by forming an upper layer to become a protective layer 5 on the means and then etching the upper layer. Reference numeral 56 denotes a heat acting surface that supplies power to the heat generating portion 6a of the heat generating resistor layer 2 formed between the electrodes 3 and 4 and transmits the generated heat to the outside of the element. ．．
This is a step that occurs between 4 and 4.

When forming such a heat generating resistor element, in the conventional heat generating resistor element as illustrated in FIG. Because of this tendency, the thickness of the protective layer had to be thicker than necessary (usually twice or more that of the TL electrode). However, in the present invention, the protective layer 5
After forming the upper layer that becomes layer 5, etching is performed on the upper layer, and the upper layer is repeatedly laminated and etched as necessary, which may cause the pinholes and cracks mentioned above. Layer defects such as non-uniform film quality can be eliminated. In addition, since the lamination and etching of the upper layer are repeated as necessary, the thickness of the protective layer can be set as desired. The problems associated with the thickening of the film described in No. 5 are solved, and it is possible to provide a heating resistor element that not only saves power but also has high durability and high-speed thermal response. Incidentally, in the present invention, it was sufficient that the thickness of the protective layer was 1.5 times or less the thickness of the electrode.

In the present invention, the heating resistance layer, electrode, and upper layer are formed using known raw materials, for example, by sputtering methods such as radio frequency (RF) sputtering, chemical vapor deposition (
It is formed using a well-known film forming method such as a CVD method or a vacuum evaporation method without particular limitation. Regarding etching after laminating the upper layer, for example, wet etching using various etching solutions, dry etching such as sputter etching, reactive etching (RIE), etc.
Although any well-known etching technique can be used without particular limitation, dry etching is preferred in view of process simplification, and sputter etching is particularly preferred.

Hereinafter, an example of the method of the present invention will be explained based on FIGS. 4(a) to 4(cl).

First, as shown in FIG. 4(a), a heat generating resistor layer 2 is formed on a desired substrate 1 using, for example, a vacuum deposition method or a sputtering method. Next, in order to form electrodes 3.4 on this heat generating resistance layer z, an electrode layer is uniformly formed on the resistance layer 2 to a desired thickness using vacuum evaporation or sputtering. Thereafter, the electrode layer and the heat generating resistor layer 2 are formed using a well-known photolithography technique.
is subjected to patterning to obtain thermal energy generating means consisting of a heating resistor layer 2 and electrodes 3.4 formed in a desired pattern on the substrate 1.

Next, as shown in FIG. 4(b), in order to form a protective layer on the thermal energy generating means, for example, Si3N4,
Upper layer 5a made of a desired material such as 5i02.5iON, Ta20c, etc. is formed to have a thickness approximately twice that of electrode 3.4 using the same vacuum deposition, sputtering, or CVD method as described above.

Thereafter, etching such as sputter etching is performed on the upper layer 5a to obtain a heating resistor element having a protective layer 5 formed to a desired thickness as shown in FIG. 4(C). Etching conditions such as etching gas and etching rate may be as desired depending on the material of the protective layer, etc., but for example, in the case of sputter etching, Ar gas or the like is preferably used. Further, although not specifically explained above, when the protective layer 5 is formed, a convex portion 7a as shown in FIG. 4(b) is likely to be formed in the step 7. Such protrusions 7a not only cause layer defects, but also impede heat supply to the outside of the element, so it is desirable to remove them. However, in conventional methods, the effectiveness of such protrusions 7a is It could not be removed. However, in the present invention, the protrusion 7a can be removed by etching performed after the upper layer 5a is laminated, and the fourth
A uniform and high quality protective layer 5 as shown in Figure (C) can be formed without increasing the layer thickness.

Such formation and etching of the northern layer 5a can be performed on the upper layer if performed several times, but in order to improve the function of the protective layer 5, for example, the upper layer is etched as shown in FIG. 4(d). layer 5
Repeat the formation and etching of a as necessary,
There is absolutely no problem in forming the protective layer 5. Of course, when such repetition is performed, it is not necessary to etch all of the repeatedly formed upper layers 5a, and it is sufficient to etch at least the lowermost upper layer 5a.

(Function) As described above, in the present invention, the formation and etching of the upper layer,
This process is repeated as necessary to form a protective layer, so even if the layer thickness is thin, a protective layer with no layer defects such as pinholes and good step coverage can be obtained, resulting in low power consumption. Needless to say, it is possible to provide a heating resistor element that is highly durable and exhibits high-speed thermal response.

〔Example〕

Examples of the present invention are shown below.

EXAMPLE The heat-generating resistor elements shown in FIGS. 1 and 2 were produced in the following manner according to the method shown in FIG. 4.

As the base 1, an alumina ceramic plate was used. On this substrate 1, a heat generating resistance layer 2 made of HfB2 was formed to a thickness of 1300 mm by sputtering. Next, on the heat generating resistor layer 2, an A1 layer which would become the electrode 3.4 was formed to a thickness of 5,000 layers by vacuum evaporation. After that, the A1 layer and the heat generating resistor layer 2 are subjected to a photolithography process, and the size of the heat generating part 6a is 100 ux 100.
A thermal energy generating means having a circuit pattern including the A1 electrode 3.4 and having a resistance value of 60Ω was formed on the substrate 1 using the steps shown in FIG.

Next, an upper layer 5a of 5i07 was formed on the means using an RF sputtering device to a thickness of about 5000 nm. Formation conditions are RF power, 1kW, pressure crab lX10
' It was done with Torr.

After forming the upper layer 5a, the layer 5a was subjected to sputter etching using a metering gas at an etching rate of 50 layers/min for about 30 minutes, so that the thickness of the layer 5a was 3500 layers. Thereafter, the etched upper layer 5a is etched with 5i in the same manner as above.
02 was further laminated to a thickness of 3,000 strands, and then etched in the same manner as described above to complete a heating resistor element having a protective layer 5 made of 5,102 with a thickness of about 5,000 strands.

The heating resistor element thus obtained had good step coverage and a high quality protective layer free from layer defects such as pinholes.

Comparative Example A heating resistor element was prepared in the same manner as in the example except that no etching was performed. The protective layer thickness is about 5000 people 4,
Step coverage was insufficient, and a protective layer thickness of approximately 100,004 mm was required to obtain sufficient step coverage.

When power was supplied to the heating resistor element of the conventional example with a layer thickness of 10,000 and the heating resistor element of the example created in this way and the durability etc. was compared, the heating resistor element of the example was (1 ) Improvements in performance were observed, such as approximately 50% reduction in power consumption, (2) approximately 40% improvement in thermal response, and (3) approximately lθ% improvement in durability.

(Effects of the Invention) As explained above, the present invention makes it possible to provide a method for producing a novel heating resistor element that not only saves power but also achieves high durability and high-speed thermal response. became.

[Brief explanation of drawings]

FIG. 1 is a partial plan view of an example of a heating resistor obtained by applying the method of the present invention, FIG. 2 is an X-Y cross-sectional view of FIG. 1, and FIG. 3 is a diagram of a conventional heating resistor. An example, Figure 4(a)
-(d) are diagrams illustrating an example of the method of the present invention. 2: Heat generating resistance layer 3.4: Electrode 5: Protective layer Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] (1) After forming at least one set of thermal energy generating means consisting of a heat generating resistive layer and at least one pair of electrodes electrically connected to the heat generating resistive layer on a substrate, an upper layer serving as a protective layer for the means is formed. A method for producing a heat generating resistor element comprising laminating the upper layer on the means, the method comprising etching the upper layer after laminating the upper layer.