KR100759253B1 - Method for menufacturing pressure sensor - Google Patents

Abstract

The present invention comprises the steps of sequentially forming an anti-reflection film, a first insulating layer and a first TiN layer on the lower metal wiring; Patterning the first TiN layer to form a first TiN layer pattern in the MIM capacitor predetermined region and the pressure sensor predetermined region, respectively; A polyimide layer, a hard mask layer, and a second insulating layer covering the first TiN layer pattern of the pressure sensor predetermined region, and a second TiN layer pattern covering a portion of the first TiN layer pattern and the second insulating layer of the MIM capacitor predetermined region. Forming each; Forming a third insulating layer covering the pressure sensor predetermined region surface; Etching the first insulating layer, the anti-reflection film below the lower metal wiring, and separating the lower metal wiring of the MIM capacitor predetermined region and the pressure sensor predetermined region; Forming an interlayer insulating film on the entire surface, forming first and second via holes exposing the polyimide layer and the second TiN layer pattern of the predetermined region of the MIM capacitor, respectively, and removing the polyimide layer through the second via holes; Forming first and second metal plugs in the first and second via holes, respectively, and forming upper metal wires connected to the first metal plugs; And forming a protective layer on the entire surface and then etching the protective layer to expose the upper portion and the upper metal wiring of the pressure sensor region.

Polyimide Layer, Pressure Sensor, MIM Capacitor

Description

Manufacturing method of pressure sensor {METHOD FOR MENUFACTURING PRESSURE SENSOR}

1A to 1L are cross-sectional views illustrating a method of manufacturing a pressure sensor according to the present invention.

<Description of the symbols for the main parts of the drawings>

100: sublayer 105: lower metal wiring

110: antireflection film 120: first insulating layer

130: first TiN layer 130a, 130b: first TiN layer pattern

140: polyimide layer 150: hard mask layer

160: second insulating layer 170a, 170b: second TiN layer pattern

180: third insulating layer 190: interlayer insulating film

200: first metal plug 210: second metal plug

220: upper metal wiring 230: first protective layer

240: second protective layer 310: first via hole

320: second via hole 400a: MIM capacitor predetermined region

400b: pressure sensor expected area

The present invention relates to a method of manufacturing a pressure sensor, and more particularly, a pressure capable of one-chip sensor module and signal processing module by simultaneously implementing a pressure sensor and an analog MIM capacitor under the upper metal wiring of a CMOS IC logic process It relates to a method for manufacturing a sensor.

In the case of a conventional vehicle pressure sensor, a sensor module for detecting an input signal from the outside and a signal processing module for processing a signal from the sensor module to specific data separately. Therefore, when either of the modules does not operate normally, not only does it drive abnormally, but also requires a lot of space.

In order to improve the problem of the conventional pressure sensor, it is necessary to make one-chip by including a sensor module manufacturing process in the conventional CMOS integration process.

This invention is made | formed in view of the above-mentioned problem, and an object of this invention is to provide the manufacturing method of the pressure sensor which can make the sensor module and the signal processing module one chip.

In order to achieve the above object, the manufacturing method of the pressure sensor according to the present invention comprises the steps of sequentially forming an anti-reflection film, the first insulating layer and the first TiN layer on the upper metal wiring; Patterning the first TiN layer to form a first TiN layer pattern in a MIM capacitor predetermined region and a pressure sensor predetermined region, respectively; Forming a polyimide layer, a hard mask layer, and a second insulating layer covering the top and sidewalls of the first TiN layer pattern of the pressure sensor predetermined region; Forming a second TiN layer pattern covering a portion of a surface of the second insulating layer and a first TiN layer pattern of a predetermined region of the MIM capacitor; Forming a third insulating layer covering an upper surface of the pressure sensor predetermined region; The exposed first insulating layer between the MIM capacitor predetermined region and the pressure sensor predetermined region and the anti-reflection film and the lower metal wiring exposed therefrom are etched to electrically connect the lower metal wiring of the MIM capacitor predetermined region and the pressure sensor predetermined region. Separating; An interlayer insulating layer is formed over the entire surface, and the first and second via holes exposing the second TiN layer pattern of the predetermined region of the polyimide layer and the MIM capacitor are formed by etching the interlayer insulating layer; Removing the polyimide layer through via holes; Forming first and second metal plugs respectively filling the first and second via holes, and forming upper metal wires connected to the first metal plugs; And forming a protective layer over the entire surface, and then etching the protective layer to expose the pressure sensor region and the upper metal wiring.

EMBODIMENT OF THE INVENTION Hereinafter, preferred embodiment of this invention is described in detail with reference to an accompanying drawing.

First, referring to FIG. 1A, the sub layer 100, the lower metal wiring 105, the antireflection film 110, the first insulating layer 120, and the first TiN layer 130 are sequentially formed. In this case, for example, the lower metal wiring 105 is formed of Al using the PVD method, and the antireflection film 110 is formed of TiN using the PVD method. In addition, the first insulating layer 120 may be formed of nitride using PE-CVD.

Referring to FIG. 1B, after forming a mask for patterning the first TiN layer 130, the first TiN layer 130 is patterned to form a first in the capacitor predetermined region 400a and the pressure sensor predetermined region 400b. TiN layer patterns 130a and 130b are formed, respectively. Since the mask process for patterning the first TiN layer 130 does not require high precision, it is possible to use an i-line process, and a gas combination of Cl ₂ / BCl ₃ is used for the TiN etching.

Referring to FIG. 1C, a polyimide layer 140 and a hard mask layer 150 covering upper and sidewalls of the first TiN layer pattern 130b of the predetermined pressure sensor region 400b are formed. Here, the thickness of the polyimide layer 140 is about 5000 kPa to 10000 kPa. In addition, the polyimide layer 140 is formed by coating at a spin coating speed of 2000 rpm to 7000 rpm, is formed at a temperature of 50 ° C. to 120 ° C. and soft baking for 1 minute to 5 minutes, and a temperature of 150 ° C. to 210 ° C. It is desirable to perform a hard baking for minutes to 2 minutes to remove the solvent therein. In this case, in order to stabilize the polyimide layer 140, it is more preferable to perform the curing process of the polyimide layer 140 at a temperature of 400 ° C. and exposed to N ₂ gas. Forming the hard mask layer 150 on top of the polyimide layer 140 is intended to prevent the removal of the photoresist (not shown) together with the polyimide layer after the polyimide patterning. (150) is formed first, and then mask work is good. In addition, during the etching process for forming the layer surrounding the first TiN layer pattern 130b, the hard mask layer 150 may include CHF ₃ / O ₂ / Ar or CHF ₃ / CF ₄ / O ₂ / Ar. The polyimide layer 140 may be etched using O _2. However, when the polyimide layer 140 is etched, the O ₂ flow rate may be reduced to about several tens of sccm for anisotropic etching, and a bias power may be applied. desirable.

Referring to FIG. 1D, a second insulating layer 160 covering upper and sidewalls of the polyimide layer 140 and the hard mask layer 150 is formed. The second insulating layer 160 may be formed by depositing an oxide film by PE-CVD and forming a mask for forming the second insulating layer 160 using an i-line process and then etching the oxide film. In this case, preferably, the oxide film is etched by not forming a mask in a region other than the predetermined region of the pressure sensor 400b, and the etching condition of the oxide film is applied to the oxide so that the first insulating layer 120 made of nitride is not removed. The etching selectivity ratio is high. Oxide film etching conditions with a high selectivity to the oxide film are more specifically such that x / y is large or the O ₂ flow rate is low in the gas combination of C _x F _y (x and y are natural water) / O ₂ / Ar.

Referring to FIG. 1E, second TiN layer patterns 170a and 170b may be formed to cover a portion of the surface of the second insulating layer 160 and the first TiN layer pattern 130a of the MIM capacitor predetermined region 400a, respectively. The second TiN layer patterns 170a and 170b are formed by depositing TiN using a PVD method, forming a mask using an i-line process, and patterning each using a gas combination of Cl ₂ / BCl ₃ . .

Referring to FIG. 1F, a third insulating layer 180 covering the upper surface of the pressure sensor predetermined region 400b is formed. The third insulating layer 180 is formed by, for example, depositing an oxide film by PE-CVD, forming a mask by an i-line process, and then etching the oxide film. Preferred etching conditions of the oxide film are the same as those of the second insulating layer 160, and thus, detailed description thereof will be omitted.

Referring to FIG. 1G, the exposed first insulating layer 120 between the MIM capacitor predetermined region 400a and the pressure sensor predetermined region 400b and the anti-reflection film 110 and the lower metal wiring 105 below are etched. Thus, the lower metal wiring 105 of the MIM capacitor predetermined region 400a and the pressure sensor predetermined region 400b is electrically disconnected. In this case, a mask for etching is first formed. Since the mask used at this time requires relatively high precision, it is preferable to use a photoresist for KrF or ArF (not shown). In addition, for example, a metal combination of CHF ₃ / O ₂ / Ar or CHF ₃ / CF ₄ / O ₂ / Ar is used for etching the first insulating layer 120 made of nitride, and the lower metal wiring made of Al is used. For etching 105, a gas combination of Cl ₂ / BCl ₃ can be used. However, in the case of using Cl-based etchant, after the etching process is completed, the photoresist strip process and the wet cleaning process are performed without exposure to the air to prevent continuous corrosion reaction due to contact with the atmosphere. It is preferable to carry out.

Referring to FIG. 1H, an interlayer insulating layer 190 is formed over the entire surface, and the first and second TiN layer patterns 170a of the polyimide layer 140 and the MIM capacitor predetermined region 400a are respectively exposed. After etching the second via holes 310 and 320, the polyimide layer 140 is removed through the second via holes 320. Since the mask for forming the via holes 310 and 320 requires high precision like the Al etching mask, it is preferable to use a photoresist for KrF or ArF (not shown). In the via etching step, C _x H _y F _z (x, y are non-negative positive integers) / O ₂ / Ar may be used. After the via etching process is completed, the via mask photoresist (not shown) is removed. At this time, the O ₂ flow rate is sufficiently flowed from 100 sccm to 2000 sccm to simultaneously remove the polyimide layer 140.

Referring to FIG. 1I, the first and second via holes 310 and 320 are buried in tungsten, for example, by CVD to form the first and second metal plugs 200 and 210, respectively. In this case, in order to smoothly embed tungsten, it is preferable to deposit a Ti / TiN barrier metal layer (not shown) having a thickness of 30 kPa to 200 kPa by PVD method first. In addition, when the tungsten is buried, it is advisable to finish the entire surface by the CMP process for isolation between the plugs.

Referring to FIG. 1J, an upper metal line 220 connected to the first metal plug 200 is formed. In this case, for example, Al deposition is first performed, BARC or Oxynitride is applied as an antireflection film, a mask is formed, and Al is then etched by a gas combination of Cl ₂ / BCl ₃ . An upper metal wiring 220 made of Al is formed.

Referring to FIG. 1K, a protective layer is formed on the entire surface. The protective layer includes a first protective layer 230 that buffers stress from the nitride and a second protective layer 240 that serves to prevent infiltration of external impurities due to its high density and hardness as a final protective layer. It is preferable to have a double structure. In this case, for example, the first protective layer 230 may be formed of an oxide film using the PE-CVE method, and the second protective layer 240 may be formed of a PE-nitride film having excellent external impurity protection effect.

Referring to FIG. 1L, the protective layers 230 and 240 are etched to expose the pressure sensor region 400b and the upper metal wiring 220. Exposing the upper portion of the pressure sensor region 400b may allow the pressure sensor to measure external pressure, and exposing the upper metal wiring 220 may include a metal pad connected to the upper metal wiring 220. To form on top of it. At the time of etching of the protective layer 230 and 240, and using a gas combination of the C _x H _y F _z (x, y, z is a positive non-negative integer) / O ₂ / Ar, O ₂ plasma or ozone Wet cleaning is performed after removing the photoresist used as a mask.

According to the method of manufacturing a pressure sensor according to the present invention, the sensor module and the signal processing module can be one-chip by simultaneously implementing the pressure sensor and the analog MIM capacitor under the upper metal wiring of the CMOS IC logic process, thereby greatly reducing the chip size. Manufacturing costs can be significantly lowered. In addition, device reliability can be improved by simplifying the pressure sensor manufacturing process.

Claims (11)

Sequentially forming an anti-reflection film, a first insulating layer, and a first TiN layer on the lower metal wiring; Patterning the first TiN layer to form a patterned first TiN layer pattern in a MIM capacitor region to be used as a MIM capacitor and a pressure sensor region to be used as a pressure sensor, respectively; Forming a polyimide layer covering the upper portion of the patterned first TiN layer pattern on the pressure sensor region, forming a hard mask layer covering the upper portion of the polyimide layer, and a second insulating layer covering the upper portion of the hard mask layer Forming a; Forming a second TiN layer pattern respectively covering a portion of the second insulating layer surface and the first TiN layer pattern of the MIM capacitor region; Forming a third insulating layer covering an upper surface of the pressure sensor region; Etching the exposed first insulating layer between the MIM capacitor region and the pressure sensor region and the bottom anti-reflection film and the lower metal wiring to electrically separate the lower metal wiring of the MIM capacitor region and the pressure sensor region; An interlayer insulating film is formed over the entire surface, a first via hole is etched to expose the second TiN layer pattern of the MIM capacitor region to the outside of the top of the interlayer insulating film, and the polyimide layer is formed on the upper outside of the interlayer insulating film. Etching the second via hole to expose the second via hole, and then removing the polyimide layer through the second via hole; Forming first and second metal plugs respectively filling the first and second via holes, and forming upper metal wires connected to the first metal plugs; And After forming a protective layer over the entire surface, etching the protective layer to expose the pressure sensor region and the upper metal wiring. The method of claim 1, The etching process of the lower metal wiring is performed using a gas combination of Cl ₂ / BCl ₃ manufacturing method of a pressure sensor. The method of claim 1, Forming the first and second metal plugs, Depositing a Ti / TiN barrier metal layer having a thickness of 30 GPa to 200 GPa by PVD; Forming a tungsten layer filling the first and second via holes over the entire surface; And And a step of flattening and etching the tungsten layer by a CMP process. The method of claim 1, The step of forming the protective layer, Forming a first protective layer from an oxide film using a PE-CVE method; And A method of manufacturing a pressure sensor, comprising the step of forming a second protective layer with a PE-nitride film. The method of claim 4, wherein The etching process of the protective layer and the etching process of the first and second via holes may be performed using a gas combination of C _x H _y F _z (x, y, z are non-negative positive integers) / O ₂ / Ar. Method of producing a pressure sensor, characterized in that carried out. The method of claim 1, In the etching process of the lower metal wiring and the etching process of the first and second via holes, the etching mask is a KrF or ArF photoresist. The method of claim 1, The first insulating layer is formed by depositing nitride by PE-CVD, And the second and third insulating layers are formed of an oxide film using PE-CVD. The method of claim 1, The polyimide layer has a thickness of 5000 kPa to 10,000 kPa. The method of claim 1, The polyimide layer was spin-coated at a rotational speed of 2000 rpm to 7000 rpm and subjected to soft baking at a temperature of 50 ° C. to 120 ° C. for 1 minute to 5 minutes and a temperature of 150 ° to 210 ° C. for 1 minute to 2 minutes. Hard baking was performed, The manufacturing method of the pressure sensor characterized by the above-mentioned. The method of claim 9, The polyimide layer is a method of manufacturing a pressure sensor, characterized in that the hardened at a temperature of 400 ℃ and the state exposed to the N ₂ gas. The method of claim 1, Removing the polyimide layer, the pressure sensor manufacturing method characterized in that it is carried out using an O ₂ plasma flow rate of 100sccm to 2000sccm.

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