JP2864844B2 - Method of forming resistor structure in semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resistor structure in a semiconductor device, and more particularly to an improvement in a method for forming a resistor structure formed using a polycrystalline silicon layer.

[0002]

2. Description of the Related Art For a resistor using a polycrystalline silicon layer in a semiconductor integrated circuit, it is one of the important issues in manufacturing to reduce the temperature coefficient of a generally set resistance value.

Here, FIGS. 6 and 7 schematically show the outlines of resistor structures according to other conventional examples designed to reduce the temperature coefficient.

In each of the conventional examples shown in FIGS. 6 and 7, reference numeral 1 denotes an oxide film formed on a semiconductor substrate (not shown). Reference numerals 2a and 2b denote resistor layers each using a polycrystalline silicon layer according to each of the examples (FIGS. 6 and 7) selectively patterned on the oxide film 1. Each resistor layer 2
a and 2b are formed with silicide layers 3a and 3b for contact in proximity to both ends, respectively.
Here, as shown in FIG. 6, the former resistor layer 2a (corresponding to the example of FIG. 6) is formed to have a relatively large film thickness, and the impurity doping amount is increased. As shown in FIG. 7, the resistor layer 2b (corresponding to the example of FIG. 7) is formed relatively thin. Further, reference numeral 4 denotes an interlayer insulating film provided to cover each of the resistor layers 2a and 2b according to each of the above-described examples, and reference numerals 5 and 6 denote the respective silicide layers 3a and 3a through contact holes opened in the interlayer insulating film 4.
3b, a barrier metal film and an aluminum electrode.

That is, in the former conventional resistor structure shown in FIG. 6, the thickness of the resistor layer 2a is made relatively thick, and the means for increasing the doping amount of impurities is used as expected. so reduce the temperature coefficient, in a conventional resistor structure shown in the latter FIG. 7, the resistor layer 2b
Similarly, the temperature coefficient is reduced as expected by means of only forming the film thickness relatively thin.

[0006]

However, in the case of each conventional resistor structure configured as described above, the means for increasing the doping amount of impurities in the former structure may result in obtaining a high resistor. In the means for forming the film thickness of the latter structure relatively thin, when forming each silicide layer at both ends of the resistor layer, the polycrystalline silicon layer portion immediately below the corresponding formation portion disappears. This causes undesired problems such as aggregation of the silicides and increase in contact resistance.

Accordingly, the object of the present invention is to
An object of the present invention is to provide a method for forming a resistor structure in a semiconductor device of this kind, which can reduce a temperature coefficient as much as possible.

[0008]

To achieve SUMMARY OF for the] said object, the method of forming the resistor structure in a semiconductor device according to a first aspect of the invention, on the oxidation film of a semiconductor substrate surface, a first Depositing a polycrystalline silicon layer, injecting impurities into the entire surface, performing a heat treatment, and then selectively forming a resistor layer by patterning into a predetermined planar shape; A first interlayer insulating film is deposited and covered on the oxide film including the layer, and a first contact hole is opened in each corresponding portion of the first interlayer insulating film, thereby forming each of the resistor layers. Exposing a contact portion, and after removing the resist pattern, depositing a second polycrystalline silicon layer on the first interlayer insulating film including the first contact holes; Open the relevant part through the hole to the opening of the resistor layer. Implanting impurities into the entire surface and performing a heat treatment after connecting to the respective contact portions, and patterning the second polycrystalline silicon layer implanted with the impurities into a predetermined planar shape, A resistor portion is formed on each contact portion of the resistor layer so as to selectively protrude, and a silicide layer is formed on the protrusion portion of each resistor portion. A step of depositing and covering a second interlayer insulating film having a required thickness on the interlayer insulating film including the protruding portion covered with the silicide layer of each of the resistor portions; A second contact hole is opened in a corresponding portion to expose each silicide layer in each resistor portion, and further, an electrode is connected to each silicide layer through the second contact. It is intended to.

Further, a method of forming a resistor structure in a semiconductor device according to a second aspect of the present invention includes the step of
On oxidation film, after depositing a polycrystalline silicon layer, an impurity was implanted into the entire surface, and a step of heat treatment, the silicide layer directly, and a step of sputtering, the respective resist pattern as a mask a step of selectively patterning the silicide layer in a predetermined plane shape leaving the silicide layer, wherein each of the resist after pattern removal of the front Kio resistor layer composed mainly of in to resistor structure patterning a crystalline silicon layer Are selectively formed, an interlayer insulating film is formed thereon, contact holes are respectively opened in respective portions of the interlayer insulating film, and electrodes are respectively connected to the silicide layers through the contact holes. And at least steps.

Further, the method of forming the resistor structure in a semiconductor device according to a third aspect of the invention, the semiconductor substrate surface
After depositing a polycrystalline silicon layer on the oxide film of
Implanting impurities into the entire surface, performing a heat treatment to form a second oxide film and a nitride film respectively, and selectively etching away a nitride film in a region corresponding to a surface of a resistor portion later; Then, heat treatment is performed using the remaining nitride film as a mask to remove the region under the opening of the nitride film of the second oxide film.
Forming a second oxide film by growing it thicker than the second oxide film
And a second step around the nitride film and the third oxide film.
Step of exposing the polycrystalline silicon layer by removing the oxide film
And patterning the polycrystalline silicon layer into a predetermined planar shape to selectively form a resistor layer serving as a main body of the resistor structure, and only for each exposed surface of the resistor layer,
Forming a thick silicide layer by sputtering, forming an interlayer insulating film thereon, contact holes are respectively opened in respective portions of the interlayer insulating film, and electrodes are respectively formed on the silicide layer through the contact holes. And a step of connecting.

[0011] The fourth method of forming the resistor structure in a semiconductor device according to the invention, selected portions contained in the resistor portion after forming the <br/> first oxide film on a semiconductor substrate surface of the present invention Other than the thickness of about half the thickness of the resistor portion, and etching and removing the same, and depositing a polycrystalline silicon layer on the entire surface including the selected portion of the thick oxide film, A step of injecting impurities into the entire surface, performing a heat treatment, and applying and forming a resist a plurality of times; and forming a polycrystal corresponding to each of the resist and a selected portion of the first oxide film. Removing the step bulging portion by flattening the step bulging portion of the silicon layer by etch-back; and patterning the polycrystalline silicon layer into a predetermined planar shape, thereby forming a resistor as a main component of the resistor structure. Selectively form body layers, One only for the first relevant area portion on the resistor layer corresponding to the selected portion of the oxide film, and a step of selectively forming a second oxide layer, each exposed surface of the said resistor layer Only for this, a silicide layer is formed by sputtering, then an interlayer insulating film is formed thereon, and then a contact hole is opened for each corresponding portion of the interlayer insulating film. Connecting an electrode to the silicide layer through the contact hole.

Further, according to a fifth aspect of the present invention, there is provided a method of forming a resistor structure in a semiconductor device, comprising depositing a polycrystalline silicon layer on a first oxide film on a semiconductor substrate surface, And heat-treated by injecting impurities into
Only the selected portion included in the resistor portion is removed by etching while leaving only about half the thickness of the resistor portion to form a resistor layer in which the selected portion is a recess, Along with the formation of the second oxide film on these,
A step of applying and forming a resist on each of the plurality of times, and a step swelling portion of the second oxide film formed corresponding to each of the resist and the resistor layer other than the selected portion by etching back. by flattening the embedded the selection in portions with the oxide film, and a step of exposing the non-relevant selected portions only for the appropriate exposed portions of the resistor layer corresponding to the selected portion, by sputtering a sheet Risaido layer Forming an interlayer insulating film thereon, opening contact holes in respective portions of the interlayer insulating film, and connecting an electrode to each silicide layer through each of the contact holes. It is characterized by including at least.

[0013]

[Action] Therefore, when the method of this invention, has a structure without thereby eliminate the polycrystalline silicon layer of silicide contacts portion, first and third, each of the embodiments of the fourth and fifth, polycrystalline Other parts where the silicon layer is silicided
By means of forming a region thicker than the region of
In the embodiment, this is achieved by means of directly sputtering the silicide layer so as not to react with silicon.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following, each of the embodiments of the resistor structure and the method of manufacturing the same in the semiconductor device according to the present invention will be described.
This will be described in detail with reference to FIGS.

First, FIGS. 1A to 1E schematically show major steps in a method of manufacturing a resistor structure in a semiconductor device to which a first embodiment of the present invention is applied. FIG.

In the method of the first embodiment, first, on a thick oxide film 11 on a semiconductor substrate (not shown), a required film thickness (in this case, in the same manner as in the above-described conventional example of FIG. 6). , A relatively thin) polycrystalline silicon layer, and impurities (eg, As ⁺ , P ⁺
N-type impurities) and heat treatment.
By patterning into a predetermined planar shape, a resistor layer 12 which is a main component of the resistor structure is selectively formed (FIG. 1A).

Next, the oxide film 1 including the resistor layer 12
A first interlayer insulating film 13 having a required film thickness is deposited and covered on the substrate 1 and a resist pattern 14 is used as a mask (the mask using the resist pattern 14 corresponds to an emitter opening mask in a bipolar process as described later). 1), first contact holes 13a, 13a are respectively opened in corresponding portions of the first interlayer insulating film 13 to expose respective contact portions of the resistor layer 12 (FIG. 1B). ).

After removing the resist pattern 14 used for the mask, the first contact holes 13a, 1
A second polycrystalline silicon layer 15a having a required film thickness is deposited on the first interlayer insulating film 13 including the first contact holes 3a, and the corresponding portions passing through the first contact holes 13a are replaced with the resistor layers 12a. 1 (a), respectively.
An impurity (eg, an N-type impurity such as As ⁺ , P ⁺ ) is implanted into the entire surface (this impurity implantation corresponds to the impurity implantation into the emitter in the bipolar process).
In addition, heat treatment is performed (FIG. 1 (c)).

Subsequently, as in the case of the step of FIG. 1A, the second polycrystalline silicon layer
is patterned into a predetermined planar shape (this patterning of the polycrystalline silicon layer is equivalent to a polycrystalline silicon emitter in a bipolar process), and the resistor portions 12a, 12a are formed on the respective contact portions of the resistor layer 12.
Are formed so as to selectively protrude partially,
Further, on the protruding portions of the respective resistor portions 12a, 12a, silicide layers (eg, TiSi ₂ ) 16, 16
Is formed on each of them (FIG. 1 (d)).

Thereafter, a second interlayer insulating film 17 having a required thickness is formed on the interlayer insulating film 13 including the protrusions covered with the silicide layers 16 of the resistor portions 12a.
Is deposited and covered. As in the case of the step of FIG.
Second contact holes 17a, 17a are respectively opened in corresponding portions of the second interlayer insulating film 17, and the respective silicide layers 16, 16 in the respective resistor portions 12a, 12a are formed.
And the second contact holes 17 are exposed.
a and 17a, the barrier metal films 18 and 18 and the aluminum electrodes 19 and 19 are formed on the silicide layers 16 and 16 respectively.
Are connected to each other, thereby obtaining the expected resistor structure (FIG. 1 (e)).

Therefore, in the resistor structure according to the first embodiment having the above-described structure, even if the main resistor layer 12 is formed of a relatively thin polycrystalline silicon layer, the resistor layer is not affected. On each contact portion of the layer 12, each of the resistor portions 12a,
Since the substantial film thickness at each contact portion is made sufficiently thick by connecting and forming the silicide layer 16 on each of the resistor portions 12a, 12a.
In forming the coating of No. 16, the disappearance of the polycrystalline silicon layer portion immediately below the relevant portion as in the conventional example described above is eliminated, and disadvantages such as aggregation of the respective silicides and increase in contact resistance can be easily achieved. It can be improved.

Another advantage of the resistor structure according to the first embodiment is that the manufacturing process can directly introduce the step of forming a polycrystalline silicon emitter in a bipolar process. In other words, this means that a desired resistor structure using a polycrystalline silicon layer can be formed without necessarily increasing the number of steps in the bipolar process.

FIGS. 2 (a) to 2 (e) are cross-sectional views schematically showing main steps in a method of manufacturing a resistor structure in a semiconductor device to which a second embodiment of the present invention is applied. FIG.

In the method of the second embodiment, first, on a thick oxide film 21 on the surface of a semiconductor substrate (not shown), a required film thickness (in this case, in the same manner as in the above-described conventional example of FIG. 6). (Relatively thin) polycrystalline silicon layer 22a is deposited, and impurities (eg, As ⁺ , P ⁺
N-type impurities, etc.) and heat treatment are performed (FIG. 2A), and then a silicide layer (for example, TiSi ₂
2a) is directly sputtered (FIG. 2 (b)), and each of these resist patterns 2 obtained by photolithography is used.
Using the masks 4 and 24 as masks, for example, the silicide layer 23a is selectively patterned into a predetermined planar shape with a hydrofluoric acid-based solution to leave the silicide layers 23 and 23 (FIG. 2).
(c)).

Next, the respective resist patterns 24, 2
After removing 4, the first polycrystalline silicon layer 22 a is patterned (FIG. 2D) to selectively form a resistor layer 22 which is a main component of the resistor structure. After the insulating film 25 is formed, contact holes 25a, 25a are respectively opened in respective portions of the interlayer insulating film 25, and the barrier metal films 26 are respectively formed in the silicide layers 23, 23 through the contact holes 25a, 25a. , 26
And the aluminum electrodes 27, 27, thereby obtaining the expected resistor structure (FIG. 2 (e)).

Therefore, in the method of the second embodiment,
As in the case of the first embodiment, each silicide layer 23,
23 is preliminarily formed of TiSi ₂ or the like,
Even if the polycrystalline silicon layer 22a is formed thin,
A good contact can be obtained without fear that this disappears.

In the method of the third embodiment, first, on a thick oxide film 31 on a semiconductor substrate (not shown), a required film thickness (in this case, in the same manner as in the above-described conventional example of FIG. 7). , A relatively thick (polysilicon) layer 32a, and impurities (for example, As ⁺ , P ⁺
(FIG. 3A), heat treatment is performed to form a thin oxide film 33 and a nitride film 34, respectively, and a nitride film corresponding to a region which will later become a resistor surface. 34 is selectively removed by etching (FIG. 3)
(b)).

Subsequently, heat treatment is performed using the remaining nitride film 34 as a mask to selectively form a thick oxide film 35, and the nitride film 34 used for this mask is removed until the polycrystalline silicon layer 32a is exposed. (FIG. 3 (c)).

Thereafter, the polycrystalline silicon layer 32a is patterned into a predetermined planar shape to selectively form the resistor layer 32 which is the main component of the resistor structure. Only, a thick silicide layer (eg, TiSi ₂ ) 36 is formed by sputtering, and an interlayer insulating film 37 is further formed thereon (FIG. 3D). Contact holes 37a, 37a are respectively opened in the corresponding portions, and barrier metal films 38, 38 and aluminum electrodes 39, 38 are formed in the silicide layer 36 through the contact holes 37a, 37a, respectively.
39, and the expected resistor structure is obtained in this manner (FIG. 3 (e)).

Therefore, also in the method of the third embodiment,
As in the case of the first embodiment, a good contact can be obtained.

FIGS. 4A to 4E schematically show the main steps in a method of manufacturing a resistor structure in a semiconductor device to which a fourth embodiment of the present invention is applied. FIG.

In the method of the fourth embodiment, firstly, except for the selected portion 41a included in the resistor portion later in the thick oxide film 41 on the surface of the semiconductor substrate (not shown), this is applied to the resistor portion. Etching is removed while leaving the film thickness of about half of the film thickness (FIG. 4A).

Next, on the entire surface including the selected portion 41a of the thick oxide film 41, the required thickness (in this case, it is relatively thin as in the case of the above-described conventional example of FIG. 6). After the polycrystalline silicon layer 42a is deposited, impurities (for example, N-type impurities such as As ⁺ and P ⁺ ) are deposited on the entire surface thereof.
And heat treatment is performed, and resists 43a, 43b, and 43c are further applied and formed a plurality of times (FIG. 4B).

Subsequently, the respective resists 43a, 43
b, 43c and the stepped portion of the polycrystalline silicon layer 42a formed corresponding to the selected portion 41a of the thick oxide film 41 are flattened by etch back,
The step bulging portion is removed (FIG. 4C).

Further, the polycrystalline silicon layer 42a
Is patterned into a predetermined planar shape to selectively form a resistor layer 42 which is a main component of the resistor structure, and a resistor layer 42 corresponding to a selected portion 41a of the thick oxide film 41.
An oxide film 44 of the same thickness is formed only in the corresponding region above.
(FIG. 4 (d)), and a silicide layer (eg, TiSi ₂ or the like) is formed only on each exposed surface of the resistor layer 42 as in the case of the third embodiment. 45 is formed thick by sputtering, and thereafter, an interlayer insulating film 46 is formed thereon. Then, contact holes 46a, 46a are respectively opened to respective portions of the interlayer insulating film 45, and these are formed. Each contact hole 46a, 46a
To connect the barrier metal films 47, 47 and the aluminum electrodes 48, 48 to the silicide layer 45, respectively, and thus obtain the expected resistor structure (FIG. 4).
(e)).

Therefore, also in the method of the fourth embodiment,
As in the case of the first embodiment, a good contact can be obtained.

Next, FIGS. 5A to 5E schematically show the main steps in a method of manufacturing a resistor structure in a semiconductor device to which a fifth embodiment of the present invention is applied. FIG.

In the method of the fifth embodiment, first, a thick film 51 on a semiconductor substrate (not shown) is coated with a required film thickness (in this case, as in the case of the above-described conventional example of FIG. 7). , A relatively thick polycrystalline silicon layer 52a, and impurities (for example, As ⁺ , P ⁺
(FIG. 5 (a)), heat treatment is performed, and only the selected portion included in the resistor portion is reduced to a film thickness of approximately half the thickness of the resistor portion. By removing the resist layer 52 only by etching, the resist layer 52 is formed in which the corresponding selected portion is recessed, and the resists 54a and 54b are formed a plurality of times while forming the oxide film 53 thereon. , 54c are applied to each of them (FIG. 5B).

Subsequently, each of the resists 54a, 54
b, 54c and the stepped portion of the oxide film 53 formed corresponding to portions other than the selected portion of the resistor layer 52 are flattened by etch-back, so that the inside of the selected portion is the oxide film 52a. And the portion other than the selected portion is exposed (FIG. 5C).

After that, silicide layers (for example, TiSi ₂ etc.) 55, 55 of the same thickness are sputtered only on the corresponding exposed portions of the resistor layer 42 corresponding to the selected portions 41 a, and An interlayer insulating film 56 is formed thereon.
Are formed, contact holes 56a, 56a are respectively opened in respective portions of the interlayer insulating film 56, and the barrier metal films 57, 57 are formed in the silicide layers 55 through the contact holes 56a, 56a, respectively. By connecting the aluminum electrodes 58, 58, the expected resistor structure is obtained in this way (FIG. 5 (d)).

Therefore, also in the method of the fifth embodiment,
As in the case of the first embodiment, a good contact can be obtained.

As described above, in short, in each of the above embodiments, in any case, the structure is such that the polycrystalline silicon layer in the silicide contact portion is not lost. In the third, fourth, and fifth embodiments, means for forming a thick polycrystalline silicon layer to be silicided in advance is employed. In the second embodiment, the silicide layer is directly sputtered to form silicon and silicon. Adopts a means that does not react.

[0043]

As described above in detail in each embodiment, according to the present invention, even if the resistance portion of the polycrystalline silicon layer is formed thin, the polycrystalline silicon layer does not disappear. As a result, aggregation of silicide and increase in contact resistance can be prevented beforehand.
As a result, there is a feature that a stable resistor structure having a small temperature coefficient can be easily obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view schematically showing main steps of a method for manufacturing a resistor structure in a semiconductor device to which a first embodiment of the present invention is applied;

FIG. 2 is a cross-sectional view showing each of the main steps sequentially and schematically.

FIG. 3 is a cross-sectional view showing each of main steps sequentially and schematically.

FIG. 4 is a cross-sectional view showing each of the main steps sequentially and schematically.

FIG. 5 is a cross-sectional view showing each of the main steps sequentially and schematically.

FIG. 6 is a cross-sectional view schematically showing an outline of a conventional resistor structure.

FIG. 7 is a cross-sectional view schematically showing an outline of another conventional resistor structure.

[Explanation of symbols]

 Reference Signs List 11 thick oxide film on semiconductor substrate surface 12 resistor layer (first polycrystalline silicon layer) 13 first interlayer insulating film 13a first contact hole 14 resist pattern 15 second polycrystalline silicon layer 16 silicide layer 17th 2 interlayer insulating film 18 barrier metal film 19 aluminum electrode 21 thick oxide film on semiconductor substrate surface 22 resistor layer 23 silicide layer 24 resist pattern 25 interlayer insulating film 26 barrier metal film 27 aluminum electrode 31 thick oxide film on semiconductor substrate surface 32 Resistor layers 33, 35 Oxide film 34 Nitride film 36 Silicide layer 37 Interlayer insulating film 38 Barrier metal film 39 Aluminum electrode 41 Thick oxide film on semiconductor substrate surface 42 Resistor layers 43a, 43b, 43c Resist 44 Oxide film 45 Silicide layer 46 Interlayer insulating film 47 Barrier metal film 48 Aluminum electrode 51 Half Thick oxide film on conductor substrate surface 52 Resistor layer 53 Oxide film 54a, 54b, 54c Resist 55 Silicide layer 56 Interlayer insulating film 57 Barrier metal film 58 Aluminum electrode

Continuation of the front page (56) References JP-A-62-89341 (JP, A) JP-A-61-61450 (JP, A) JP-A-62-35554 (JP, A) JP-A-62-290165 (JP, A) JP-A-3-268458 (JP, A) JP-A-3-22561 (JP, A) JP-A-63-65664 (JP, A) JP-A-3-19272 (JP, A) 1-149446 (JP, A) JP-A-2-58833 (JP, A) JP-A-63-184355 (JP, A) JP-A-1-260850 (JP, A) JP-A-62-118569 (JP, A) A) JP-A 1-260849 (JP, A) JP-A 62-89341 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01L 27/04 H01L 21/822

Claims (5)

(57) [Claims] To 1. A semiconductor substrate surface of the oxidation film, after depositing the first polysilicon layer, an impurity was implanted into the entire surface, and then subjected to heat treatment, in a predetermined planar shape Patterning to selectively form a resistor layer; depositing a first interlayer insulating film on the oxide film including the resistor layer; and forming a first interlayer insulating film on each of the corresponding portions of the first interlayer insulating film. A step of opening each contact hole and exposing each contact portion of the resistor layer; and removing the resist pattern.
A second polycrystalline silicon layer is deposited on the first interlayer insulating film including the first contact holes, and a corresponding portion passing through the first contact holes is opened in the resistor layer. A step of injecting impurities into the whole surface and performing a heat treatment after being connected to each contact portion, and patterning the second polycrystalline silicon layer into a predetermined planar shape;
Forming a resistor portion on each contact portion of the resistor layer so as to selectively protrude, and forming a silicide layer on the protrusion portion of each resistor portion; A second interlayer insulating film having a required thickness is deposited on the interlayer insulating film including the protrusion covered by the silicide layer of each of the resistor portions, and a second interlayer insulating film is formed on each of the corresponding portions of the second interlayer insulating film. 2 contact holes are respectively opened to expose the respective silicide layers in the respective resistor portions,
Connecting the electrode to each silicide layer through the second contact. To 2. A semiconductor substrate surface of the oxidation film, after depositing a polycrystalline silicon layer, an impurity was implanted into the entire surface, and a step of heat treatment, the entire surface to the silicide layer directly, sputtering a step of the steps of leaving the silicide layer is selectively patterning the silicide layer in a predetermined planar shape to each resist pattern as a mask, after removal of the respective resist patterns by patterning the polycrystalline silicon layer After selectively forming a resistor layer serving as a main body of the resistor structure, and forming an interlayer insulating film thereon, contact holes are respectively opened in corresponding portions of the interlayer insulating film. Connecting a respective electrode to each silicide layer through a contact hole. A method for forming a resistor structure in a semiconductor device, the method comprising: To 3. A semiconductor substrate surface first oxide film on, in terms of depositing the multi-binding <br/> crystal silicon layer, an impurity is implanted into the entire surface, the second respectively subjected to heat treatment oxide film and thereby forming a nitride film, after the resistor portion is selectively removed by etching the nitride film on the surface and a region corresponding partial steps and, the second by heat-treating the remaining nitride film as a mask of
A region of the oxide film below the opening of the nitride film is formed by the second acid
Forming third oxide film by growing thicker than oxide film
And the first and second oxide films around the nitride film and the third oxide film.
2 to remove the oxide film to expose the polycrystalline silicon layer.
That step and, wherein with the polycrystalline silicon layer is patterned into a predetermined planar shape to selectively form a resistor layer made mainly of the resistor structure, only the respective exposed surfaces of the resistive layer, a silicide form shape by sputtering layer, forming an interlayer insulating film over these, each is open a contact hole in each corresponding portion of the interlayer insulating film, through the respective contact holes, each electrode to the silicide layer A method for forming a resistor structure in a semiconductor device, comprising at least a step of connecting. 4. A step of forming a first oxide film on the surface of the semiconductor substrate, and etching and removing a portion other than a selected portion included in the resistor portion while leaving the film only about half in thickness. 1
Depositing a polycrystalline silicon layer on the entire surface including the selected portion of the oxide film, injecting impurities into the entire surface, performing heat treatment, and then applying and forming a resist a plurality of times. Removing the step bulging portions by flattening the step bulging portions of the polycrystalline silicon layer formed corresponding to the selected portions of the resist and the first oxide film by etch-back, and Patterning the polycrystalline silicon layer into a predetermined planar shape to selectively form a resistor layer that is a main component of the resistor structure, and to form a resistor layer corresponding to a selected portion of the first oxide film on the resistor layer of only the corresponding area portion, and the step of selectively forming a second oxide layer, wherein only the respective exposed surface of the resistor layer, was formed by sputtering a silicide layer, on these After forming an interlayer insulating film, Forming contact holes for respective portions of the interlayer insulating film, and connecting an electrode to a silicide layer through each of the contact holes. Method. 5. After depositing a polycrystalline silicon layer on a first oxide film on a semiconductor substrate surface, injecting impurities into the entire surface and performing a heat treatment, only for a selected portion included in the resistor portion. This is removed by etching while leaving only about half the film thickness of the resistor portion, thereby forming a resistor layer in which the selected portion is concave, and a second layer is formed thereon.
A step of applying a resist to each of the resist layers a plurality of times in conjunction with the formation of the oxide film, and a step of forming the second resist layers corresponding to portions other than the selected portions of the resist and the resistor layer.
Flattening the stepped portion of the oxide film with an etch back to bury the selected portion with an oxide film and exposing portions other than the selected portion; and exposing the resistor layer corresponding to the selected portion to a corresponding portion. only the portion was formed by sputtering a sheet Lisa <br/> id layer, and in terms of forming an interlayer insulating film is formed thereon, respectively to open a contact hole in each corresponding portion of the interlayer insulating film And a step of connecting an electrode to each silicide layer through each of the contact holes.