JPH11135733A - Manufacture of thin-film resistor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize high selectivity of a barrier metal layer and a thin-film resistor layer and high precision for the etching treating process of a thin-film resistor. SOLUTION: A tin-film resistor 12 is formed on an inter-layer insulated film 13 provided on a substrate 11. For the resistor 12, a CrSiN film 14 and a TiW film 15 are laminate-formed, a mask pattern 28 are formed by photoresist, and two steps of consecutive dry etching treatment is executed. The film 15 is supplied with an etching gas on a condition of enriching fluorine radical and is selectively etched, and the CrSiN film is supplied with an etching gas on a condition of enriching oxygen radical and is selectively etched. Thereby, a hem drawing phenomenon in the neighborhood of a mask due to etching is suppressed for precise etch-treatment of the mask pattern.

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 resistor having a desired shape by etching a thin film resistor layer and a barrier metal layer laminated on a substrate surface.

[0002]

As a semiconductor device, in particular, in an IC (integrated circuit), there is a semiconductor device in which a thin-film resistor is formed on an insulating film as a constituent element. And lower costs. In this case, a CrSi-based material, such as CrSi or CrSiN, whose resistance can be adjusted by laser is used as the thin film resistor.

FIG. 8 shows a material for a thin film resistor such as Cr
The manufacturing process of a thin film resistor in the case of using SiN is shown. An insulating separation film and circuit elements such as MOSFETs and bipolar transistors (not shown) are formed on a single crystal silicon substrate 1 serving as a substrate by a known method (not shown), and are used as interlayer insulating films in order to ensure insulation with metal wiring. The silicon oxide film 2 is deposited and formed by a CVD method, and heat treatment is performed to improve the film quality.

Thereafter, a CrSi-based film 3 as a thin-film resistor layer is formed on the silicon oxide film 2 and a TiW film 4 as a barrier metal layer is formed by lamination. Subsequently, a photoresist layer 5 patterned into a predetermined shape by a photolithography process is provided (see FIG. 8A), and using this as a mask member, the TiW film 4 is etched by a well-known wet etching process to form a CrSi-based film 3. It is exposed (see FIG. 3B).

Next, the CrSi-based film 3 is patterned by etching. This is performed by plasma dry etching using the photoresist layer 5 and the TiW film 4 as a barrier metal layer as a mask member (see FIG. 3C). This method is described in, for example,
No. 3,358,831. Thereafter, the photoresist layer 5 is removed, and an electrode wiring 6 made of aluminum or the like is formed by a known photolithography process (see FIG. 4D). Thus, a thin film resistor made of the CrSi-based film 3 is formed.

In the above-described manufacturing process, when the TiW film 4 serving as a barrier metal layer is etched, generation of an etching residue occurs, or FIG.
As shown in (b), since there is side etching from the edge of the photoresist layer 5 toward the inside (side etching width Δd), the original pattern dimension d1 (see FIG. 3A) is obtained. As a result, a dimension d2 (= d1-2Δd) shorter by a width 2Δd due to side etching from both sides is formed, and the variation in the processing width becomes large as a whole. This is because, when the miniaturization of the pattern for determining the minimum value of the dimension d1 is advanced, considering that the value of Δd is substantially the same as the etching accuracy, this has a large adverse effect on the whole, and as a result,
This limits the improvement of the processing accuracy.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to improve the processing accuracy in an etching process for forming such a thin film resistor, and to provide a barrier metal and a thin film resistor. An object of the present invention is to provide a method of manufacturing a thin film resistor in which resistors can be etched with high selectivity.

[0008]

According to the first aspect of the present invention, in the mask pattern forming step, a mask material layer is formed on the surface of the barrier metal layer to form a mask pattern, and then the etching process step is performed. In this method, the barrier metal layer is selectively etched by performing dry etching by plasma-activating an etching gas in which a fluorine compound gas and an oxygen gas are mixed using the mask pattern as a mask, and selectively forming the thin film resistor layer. Etch.

Thereafter, the thin film resistor can be formed on the surface of the substrate by removing the mask pattern.
As a result, in the etching processing step, the barrier metal layer and the thin film resistor layer can be continuously performed in the same dry etching step, so that the number of steps can be reduced and side etching and the like can be performed. High-precision machining can be performed with the minimum possible.

According to the second aspect of the present invention, since a compound containing chromium (Cr) and silicon (Si) is used for the thin film resistor layer, a thin film resistor having a small temperature coefficient can be obtained by employing a compound such as CrSiN. Since the element can be formed as a body, the characteristics of the element can be improved, and titanium (T
Since the layer made of i) or a compound containing tungsten (W) is formed, it is possible to prevent an undesired reaction due to direct contact with a wiring metal electrically connected to the thin film resistor layer.

According to the third aspect of the present invention, in the etching process, the barrier metal layer is selectively etched by increasing the mixing ratio of the fluorine component of the etching gas. The thin film resistor layer is not excessively etched, so that the barrier metal layer can be etched with high precision. In the next etching, the mixing ratio of the oxygen component of the etching gas is increased and the thin film resistor is selectively etched. Since the etching is performed, the thin film resistor layer can be etched using the barrier metal layer as a mask pattern, so that the thin film resistor can be formed with high accuracy.

According to the invention of claim 5, carbon tetrafluoride (C) is used as an etching gas used in the etching process.
Since a mixture of F ₄ ) gas and oxygen (O ₂ ) gas is used, the barrier metal layer containing Ti or W can be etched with CF 4 gas, while CF 4 gas can be used.
_The thin film resistor containing chromium (Cr) or silicon (Si) can be etched by the _four gases and the O ₂ gas. As a result, the etching process of the barrier metal layer and the etching process of the thin film resistor can be selectively performed only by changing the flow rate using the same kind of gas, and the etching process can be performed. It can be done without continuous gas exchange,
Processing can be performed quickly and reliably.

According to the sixth aspect of the present invention, the flow rate of oxygen with respect to the entire etching gas is set at 20 to 70% as a gas ratio when etching the barrier metal layer, so that the barrier metal layer with respect to the thin film resistor layer is formed. Can be increased in etching selectivity. Also,
In the gas ratio for etching the thin film resistor, the etching selectivity of the thin film resistor layer with respect to the oxide film formed on the underlying substrate surface is increased by setting the flow rate of oxygen to be 80% or more. It can be in a state where it has been set.

According to the seventh aspect of the present invention, since the gas ratio at the time of etching the barrier metal layer is such that the flow rate of oxygen to the entire etching gas is 50% or less, the etching selectivity of the barrier metal layer to the thin film resistor layer is increased. Can be effectively increased.

According to the eighth and ninth aspects of the present invention, an organic material containing at least a C--H bond is used as the mask material layer, and in particular, in the eighth aspect, the substrate temperature is higher than the normal temperature during the etching process. Since the heating is performed to a predetermined temperature, the etching rate of the barrier metal layer can be improved, and the C used for etching the barrier metal layer can be improved.
By the F4 gas, H of the C—H bonding portion of the mask material is
Is easily replaced with fluorine F, and the entire surface is C-F
It can be combined. By making the surface of the mask material layer a C—F bond in this manner, in the next processing step of etching the thin film resistor, even when the etching is performed under the condition that the oxygen gas ratio of the etching gas is increased, Since the O-etching resistance of the surface is increased, the amount of etching of the mask material can be suppressed when the thin-film resistor layer is etched as a result.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 schematically shows a cross section corresponding to a manufacturing process when a thin film resistor 12 is formed on a single crystal silicon substrate 11, which is a substrate. FIG. 1D shows a thin film formed by this method. 3 shows a cross-sectional configuration of the resistor 12.

In FIG. 1, a silicon oxide film 13 as an interlayer insulating film is formed on the surface of a single crystal silicon substrate 11, which is a semiconductor substrate, after a device is formed through a predetermined device forming process. ing. On the surface of the silicon oxide film 13, a thin film resistor 12 patterned in a predetermined shape is formed.

As will be described later, this thin film resistor 12
It is composed of a CrSiN film 14 (see FIG. 3A) formed by sputtering a sintered body of CrSi as a resistor substance in an atmosphere containing a nitrogen gas, and has a thickness of about 15 nm. The CrSiN film 14 forming the thin-film resistor 12 contains nitrogen so that the temperature coefficient (T
CR) can be reduced, whereby the operation stability with respect to temperature can be improved.

On the surfaces of the electrode contact portions at both ends of the thin film resistor 12, a TiW film 15 which is a barrier metal layer for preventing deterioration due to a reaction with the electrode portions is formed. The TiW film 15 is formed to have a thickness of about 250 nm. Then, an aluminum electrode pattern 16 as a metal electrode is formed so as to cover the TiW films 15 at both ends of the thin film resistor 12. Thereby, the thin film resistor 12 is formed between the aluminum electrode patterns 16.
As a result, a resistor is formed.

Next, in the process of forming the thin film resistor 12 having the above-described structure, the structure of an etching apparatus used for performing the etching process according to the present invention will be briefly described. FIG. 2 shows a schematic configuration of a chemical dry etching (Chemical Dry Etching) apparatus 17. The whole inside thereof is roughly divided into an etching reaction chamber 18 and a plasma generation chamber which communicates this with a gas passage 19. 20.

A gas introduction port 21 for introducing an etching gas is opened in the plasma generation chamber 20, and CF ₄ and O ₂ are supplied to the inside as an etching gas. Further, the waveguide 2 is provided in the plasma generation chamber 20.
The microwave is radiated to the inside through the antenna 2. When the microwave is introduced into the plasma generation chamber 20, the etching gas supplied to the inside is excited into a plasma state and activated, and the activated etching gas is etched through the gas passage 19. It is led to the reaction chamber 18.

Next, in the etching reaction chamber 18,
A gas rectifying plate 23 is provided at an upper portion, and a substrate mounting portion 24 is provided at a lower center. The gas rectifying plate 23 is arranged so as to rectify the etching gas introduced through the gas passage 19 and uniformly contact a substrate (wafer) 25 to be etched placed on the substrate placing portion 24. I have. The substrate mounting portion 24 includes a support pin 24a.
Thus, the etching process can be performed while heating the substrate 25 by radiant heat of a heating lamp 26 provided below.

An exhaust port 27 communicating with an exhaust system for discharging an etching gas and its reaction product and reducing the pressure inside the lamp is provided at a lower portion of the substrate mounting portion 24 and on a side portion of the lamp 26. In the figure, to show the flow path of the etching gas in each state, a circle indicates an etching gas before excitation, a triangle indicates an activated etching gas, and a square indicates a reaction generated by etching. Shows things.

Next, a manufacturing process for forming the thin film resistor 12 will be described with reference to FIG. First, an insulating isolation film and circuit elements such as MOSFETs and bipolar transistors are formed on the single-crystal silicon substrate 11 by a known method (not shown), and an interlayer is formed on the monocrystalline silicon substrate 11 in order to ensure insulation with metal wiring. A silicon oxide film 12 as an insulating film is deposited and formed by a CVD method. Thereafter, the silicon oxide film 12 is subjected to an annealing process under a predetermined condition to make the film quality dense.

Thereafter, a CrSiN film 14 as a thin film resistor layer is formed on the silicon oxide film 13 and a TiW film 15 as a barrier metal layer is formed by lamination. In this case, the CrSiN film 14 is formed by converting the CrSi sintered body to nitrogen (N
₂ ) It is formed by reactive sputtering in an atmosphere containing gas and argon (Ar) gas.
It is about 5 nm. The TiW film 15 is made of CrSiN
Film 14 and aluminum electrode pattern 16 formed on top
Is formed in order to prevent the reaction from deteriorating, and is similarly formed to a thickness of about 250 nm by sputtering in an argon (Ar) atmosphere.

Subsequently, a photoresist made of an organic material is applied on the TiW film 15 so as to have a thickness of, for example, about 1 μm, and is patterned into a shape corresponding to the shape of the thin film resistor 12 by a known photolithography process. Thus, a mask pattern 28 is formed (see FIG. 1A). In this case, the photoresist forming the mask pattern 28 is made of, for example, a phenol novolak resin, and the resin contains a carbon-hydrogen bond (CH bond).

Next, when the process proceeds to the etching process, using the above-described chemical dry etching apparatus 17, the Ti
The W film 15 and the CrSiN film 14 are etched. First, as the substrate 25, the single crystal silicon substrate 11
Is supported by the support pins 24 a of the substrate mounting portion 24.
In this state, an etching process is performed by introducing an etching gas.

In the etching process, the TiW film 1
2 step etching is performed on each of the CrSiN film 5 and the CrSiN film 14 under different conditions. As shown in FIG. 3, the conditions in each etching process are different by changing the mixture ratio of carbon tetrafluoride gas (CF ₄ ), which is a fluorine compound gas used mainly as an etching gas, and oxygen gas (O ₂ ). You have set.

That is, the first step, TiW film 1
In the etching process of No. 5, the value of the ratio R (%) of the flow rate of the oxygen gas to the total flow rate of the etching gas is set to 20.
By setting the range of about 70% as an appropriate range, for example, 30%, the mixing ratio of the fluorine component is set high.

In consideration of the condition that the CrSiN film 14 is hardly etched, the above ratio R (%) is obtained from FIG.
Is preferably about 50% or less, and
From the viewpoint of increasing the etching selectivity between the CrSiN film 14 and the TiW film 15, the ratio R
The value of (%) is preferably about 50% or less. The lower limit of the value of the ratio R (%) is, for example, such that the flow rate of the oxygen gas is reduced so that a film is not formed on the CrSiN film 14 and adversely affects the etching in the second step. It is preferable to be about 20% or more.

In the second step, a CrSiN film 1 is formed.
In the etching process of No. 4, the value of the ratio R (%) is set to 80 to 9
By setting the range of 5% as an appropriate range, for example, 90%, the mixing ratio of the oxygen component is set high.

As other setting conditions, the first step and the second step are set under common conditions for the etching gas pressure, the microwave output, and the substrate temperature. Etching gas pressure (Torr) is 0.6 ± 0.4
Torr is set as an appropriate range, for example, about 0.3 Torr, and the microwave output is 1000 ± 60.
The range of 0 W is set as an appropriate range, for example, 1000 W, and the substrate temperature (° C.) heated by the lamp 26 is from room temperature to
The range of 200 ° C. is set to, for example, 100 ° C. as an appropriate range.

The reason why the upper limit of the substrate temperature is 200 ° C. is that the mask material to be formed is within a range in which it can be used as an etching mask.
It is about 50 ° C. Further, setting the temperature higher than the room temperature can improve the etching rate of the barrier metal layer and promote the substitution reaction (replacement of C—H bond to C—F bond) described later by heating. This is because they also take into account that they can.

When the first and second etching processes are performed under the above-described etching conditions,
When a gas is introduced into the plasma generation chamber 20 and is irradiated with microwaves, the molecules of the etching gas are excited and the fluorine component becomes fluorine radicals, and the oxygen component becomes oxygen radicals and reacts with highly reactive particles. Become gas passage 1
9 and flows into the etching reaction chamber 18.

Then, etching is performed by the fluorine radicals and oxygen radicals.
5 and the interlayer insulating film 13 are mainly etched by fluorine radicals, and the CrSiN film 14 is mainly etched by both fluorine radicals and oxygen radicals.

This is because the fluorine radicals and oxygen radicals cause the TiW film 15, the interlayer insulating film 13 made of a silicon oxide film, and the CrSiN film 14 to react according to the following reaction formulas (1) to (3). It is considered that the etching process is performed by the occurrence of. That is, the TiW film 15 is made of titanium (T
i), tungsten (W) is etched and removed by combining with fluorine and oxygen, the CrSiN film 14 is etched and removed by combining chromium (Cr) and silicon with fluorine and oxygen, and the interlayer insulating film 13 is Silicon is combined with fluorine and etched away.

TiW + F * + O * → TiF ₄ ↑ + WF ₆ ↑ + WOFx ↑ (1) CrSi + F * + O * → CrOxFy ↑ + SiF ₄ … (2) SiO ₂ + F * → SiF ₄ … (3) In the formula, F * is a fluorine radical and O * is an oxygen radical.

The flow rates of the carbon tetrafluoride (CF ₄ ) gas and the oxygen gas are set as described above with reference to FIGS.
As shown in FIG. 3, based on the data of the etching rate (nm / min) of each film and the data of the etching selectivity between the films when the value of the mixing ratio R is changed and the horizontal axis is used, This is a result obtained as a first step etching condition effective for the TiW film 15 etching process and a second step etching condition effective for the CrSiN film 14 etching process.

In the case where such a Ti, W-based / CrSi-based thin film is continuously dry-etched, it is generally desirable to perform the etching in one step. Under the condition that the selectivity of the system is set to be high, since the amount of the photoresist removed from the mask pattern 28 by the oxygen radical increases, there is a problem that the precision of the processing pattern width of the thin film resistor 12 is reduced. The two-step etching shown in the embodiment is employed.

Therefore, in the etching process of the TiW film 15, which is the first step of the etching process, the TiW film 15 is selectively etched by performing the above-described etching conditions (see FIG. 1B). At this time, as described later, in the portion near the mask pattern 28, Ti
Since the etching rate of the W film 15 has a property of being reduced to about 2/3 as compared with other parts, 5
Over-etching of 0% or more is performed (etching is performed for 1.5 times the etching time obtained from the etching rate). Thus, it is possible to prevent the portion near the periphery from remaining as a footing state while the other portion of the TiW film 15 is removed by the etching, and to perform the etching reliably.

However, in this case, when the TiW film 15 remaining only in the vicinity of the peripheral portion is etched,
Since the SiN film 14 is exposed, the C
It is necessary to set the etching rate for the rSiN film 14 to be low. This is because the CrSiN film 14 is formed to be much thinner than the TiW film 15, so that the CrS
When the iN film 14 is removed by etching to expose the underlying interlayer insulating film 13, fluorine radicals are consumed by the etching of the interlayer insulating film 13, so that the etching rate of the TiW film 15 further decreases, and This is because the thickness of the interlayer insulating film 13 is reduced.

Therefore, in the present embodiment, in consideration of the above points, in the etching process of the TiW film 15, it is preferable to set a condition that can obtain a selectivity to the CrSiN film 14 of 10 or more. Is set as the flow rate of the etching gas shown in the first step of FIG.

The conditions for simply reducing the amount of resist removal of the mask pattern 28 without considering the etching selectivity of the CrSiN film 14 with respect to the TiW film 15 and the etching of the TiW film 15 with respect to the interlayer insulating film 12 are considered. In the two-step etching under the conditions for increasing the selectivity, problems occur in the following points.

For example, as shown in FIG. 7, when the etching process is started from FIG. 7A in a state similar to FIG. 1A, TiW generated near the periphery of the mask pattern 28 is started.
Due to the lowering of the etching rate of the film 15, a region P which has not been etched with a gentle inclination from the vicinity to the outer periphery remains in a skirted state with the underlying interlayer insulating film exposed in portions other than the mask pattern 28. (See FIG. 3B). Therefore, it is necessary to perform excessive over-etching to remove the remaining portion by etching. This is because, as a result, the problem that the shaved amount Q of the underlying interlayer insulating film 13 increases (see FIG. 3C) occurs.

That is, the CrSiN film 14 becomes the TiW film 15
Etching conditions that act as an etching stopper when etching are used. Specifically, it is necessary to consider etching conditions such that the CrSiN film 14 is not removed by the etching process until the footing region near the mask of the TiW film 15 is removed by etching.

Next, the CrSiN film 14 is etched as the second step of the etching process (FIG. 1).
(C)). In this case, etching is performed using both the mask pattern 28 and the TiW film 15 as mask members. And in this second step,
An over-etching process of 100% or more is performed. In addition,
At this time, by including a large amount of oxygen radicals as a component in the etching gas, the shaving amount of the underlying interlayer insulating film 13 due to the etching can be suppressed to about 50 nm or less. The resist material of the mask pattern 28 is etched at a high etching rate.

However, the mask pattern material is CH—H.
Since a material having a bond (here, for example, a phenol novolak resin) is contained, H is easily replaced by fluorine radicals during the etching treatment of the TiW film 15, and at this time, the substrate temperature is set to 100 ° C. and heating is performed. Has the effect of promoting the substitution reaction,
The CH bond becomes a CF bond. Since this CF bond is stronger than the CH bond, CrNiS
Even under the condition that oxygen radicals increase in the etching of the i-film 14, it is possible to suppress the substitution by reacting with the oxygen radicals. As a result, it is possible to prevent the mask pattern material itself from being etched. Will be able to The etching rate of the photoresist shown in FIG. 4 is obtained when the surface of the photoresist is not altered by fluorine radicals.

The TiW film 15 of the barrier metal layer is
Since the etching rate is substantially the same as that of the CrSiN film 14, even if the mask pattern 28 is peeled off by etching, the amount of shaving of the TiW film 15 by etching can be suppressed to about 30 nm. As a result, defects such as side etching of the TiW film 15 can be significantly improved, and the thin film resistance finally obtained with respect to the pattern width D1 of the mask pattern 28 (see FIG. 1A). The pattern width D2 of the body 12 (see FIG. 4D) can be obtained as a difference of about 0.2 μm, and patterning can be performed with high precision.

This is because, for example, as shown in FIG. 6, according to the measurement results obtained by the present inventors, for example, when each etching step obtained when the pattern width of the mask pattern 28 is set to about 4 μm is performed. It is clear from the results. That is, when the conventional wet etching process is adopted, ± 0.5 μm around 3.1 μm is used.
A large variation occurs in a width of about m. The continuous dry etching is performed in one step (etching conditions are shown in FIG. 3).
Variations occur at a width of about ± 0.3 μm around m. On the other hand, when the two-step etching employing the present embodiment is performed, it can be seen that it is formed with a small variation of about ± 0.1 μm or less around 3.8 μm with high accuracy.

Next, from the state shown in FIG. 1 (c), after removing the mask pattern 28 by a known technique, aluminum is formed on the entire surface by photolithography and the thin film resistor is formed. An etching process is performed so as to form an aluminum electrode pattern 16 that is in contact with both ends of the substrate 12. At this time, the exposed TiW film 15 on the surface of the thin film resistor 12 is removed. As a result, the thin film resistor 12 is made of Ti which is a barrier metal layer.
It is formed in a state of being in electrical contact with aluminum electrode pattern 16 via W film 15.

According to the present embodiment, the TiW film 15 serving as a barrier metal layer and the Cr film serving as a thin-film electrode layer are used.
In the etching process of the SiN film 14, a continuous dry etching process is performed in two steps, thereby reducing the number of manufacturing steps and reducing the cost. The body 12 can be formed, the process variation can be reduced during pattern formation, and stable processing can be performed. Further, it is not necessary to set a large margin in pattern design, and the occupied area in forming elements is reduced. Can be prevented from increasing.

The present invention is not limited to the above embodiment, but can be modified or expanded as follows. CDE
Instead of the apparatus, an RIE (Reactive Ion Etching) apparatus, an ICP (Inductively Coupled Plasma) apparatus, or the like can be used. A CrSi film may be used as the thin film resistor layer. Instead of the TiW film, a Ti film or a W film may be formed as a barrier metal layer. The flow rate of the etching gas can be changed to an appropriate flow rate by maintaining the mixing ratio. In this case, the pressure, the microwave output, the substrate temperature, and the like may be adjusted as necessary.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing a step of manufacturing a thin film resistor according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a chemical dry etching apparatus.

FIG. 3 is an explanatory diagram showing conditions of a dry etching process.

FIG. 4 is a correlation diagram of an etching rate of each film with respect to an oxygen mixing ratio.

FIG. 5 is a correlation diagram of an etching selectivity between respective films with respect to an oxygen mixing ratio.

FIG. 6 shows pattern width values after each etching process.

FIG. 7 is a diagram corresponding to FIG. 1 when a two-step etching process is performed under inappropriate conditions.

FIG. 8 is a diagram corresponding to FIG. 1 showing a conventional example.

[Explanation of symbols]

11 is a single crystal silicon substrate (substrate), 12 is a thin film resistor, 13 is an interlayer insulating film, 14 is a CrSiN film (thin film resistor layer), 15 is a TiW film (barrier metal layer), 16 is an aluminum electrode pattern, 17 Is a chemical dry etching apparatus, 18 is an etching reaction chamber, 19 is a gas passage,
20 is a plasma generation chamber, 26 is a lamp, and 28 is a mask pattern.

Claims (9)

[Claims] 1. A method of manufacturing a thin-film resistor having a desired shape by etching a thin-film resistor layer and a barrier metal layer laminated on a substrate surface, wherein a mask is formed on the barrier metal layer. A mask pattern forming step of forming a mask pattern by forming and patterning a material layer; and selecting the barrier metal layer by performing a dry etching process by plasma-activating an etching gas obtained by mixing a fluorine compound gas and an oxygen gas. A method of manufacturing a thin-film resistor, comprising an etching step of selectively etching and subsequently etching a thin-film resistor layer selectively. 2. The method according to claim 1, wherein a layer made of a compound containing chromium (Cr) and silicon (Si) is formed as the thin film resistor layer, and titanium is formed as the barrier metal layer. A method for manufacturing a thin film resistor, comprising forming a layer made of a compound containing (Ti) or tungsten (W). 3. The method of manufacturing a thin film resistor according to claim 2, wherein in the etching step, a mixing ratio of a fluorine component of the etching gas is increased when the barrier metal layer is selectively etched. And selectively etching the thin-film resistor by increasing the mixing ratio of the oxygen component of the etching gas. 4. The method of manufacturing a thin film resistor according to claim 1, wherein in the etching process, an etching process is performed using a plasma dry etching apparatus. Manufacturing method. 5. The method of manufacturing a thin film resistor according to claim 4, wherein, in the etching process, carbon tetrafluoride (CF ₄ ), which is a fluorine compound, is used as the etching gas.
A method for producing a thin film resistor, comprising using a mixture of a gas and an oxygen (O ₂ ) gas. 6. The method for manufacturing a thin film resistor according to claim 5, wherein an oxide film is disposed on the surface of the substrate, and the etching is performed in the etching of the barrier metal layer in the etching process. The manufacturing of a thin film resistor, wherein the ratio of oxygen gas to the flow rate in the whole gas is in the range of 20 to 70%, and the ratio is in the range of 80% or more in etching the thin film resistor layer. Method. 7. The method for manufacturing a thin film resistor according to claim 6, wherein in the etching of the barrier metal layer, the ratio of the oxygen gas to the total flow rate of the etching gas is 50% or less. A method for manufacturing a thin film resistor, wherein the method is set. 8. The method of manufacturing a thin film resistor according to claim 1, wherein the mask material for forming the mask material layer is:
An organic material containing at least a C—H (carbon-hydrogen) bond is used, and the dry etching of the barrier metal layer is performed while the substrate is heated to a predetermined temperature higher than room temperature. A method for manufacturing a thin film resistor. 9. The method for manufacturing a thin film resistor according to claim 1, wherein the mask material for forming the mask material layer is:
An organic material containing at least a C—H (carbon-hydrogen) bond is used, and in the dry etching treatment of the barrier metal layer, a fluorine compound gas component contained in the etching gas acts to remove C—C on the surface of the mask material layer. H bond to CF
A method for producing a thin film resistor, wherein a substitution reaction is performed to form a (carbon-fluorine) bond.