CN101673678B

CN101673678B - Growing method of aluminum layer and metal-insulator-metal board

Info

Publication number: CN101673678B
Application number: CN200810222115XA
Authority: CN
Inventors: 康芸; 杨瑞鹏; 聂佳相
Original assignee: Semiconductor Manufacturing International Beijing Corp
Current assignee: Semiconductor Manufacturing International Beijing Corp
Priority date: 2008-09-09
Filing date: 2008-09-09
Publication date: 2011-03-16
Anticipated expiration: 2028-09-09
Also published as: CN101673678A

Abstract

The invention provides a growing method of an aluminum layer, which is suitable for the integrated circuit manufacturing technology and comprises the step of growing an aluminum (Al) layer for manufacturing a conducting layer under the condition that the environmental temperature is lower than 270 DEG C and higher than 0 DEG C. The invention also provides a MIM board. In the embodiment of the invention which adopts the technical scheme, by growing the Al layer in the conducting layer at low environmental temperature, the surface of the grown Al layer is more smooth and uniform in thickness than the surface of the Al layer which grows at relatively higher environmental temperature, and the Al layer is suitable for the environment of miniaturized technological dimensions of IC manufacture. Moreover, because the Al layer grows at lower environmental temperature, the process of the manufacturing technology of the Al layer on the IC or MIM board is simple.

Description

The growing method of aluminium lamination and metal-insulator-metal type plate

Technical field

The present invention relates to integrated circuit (IC) manufacturing technology field, relate in particular to a kind of growing method and metal-insulator-metal type (MIM) plate of aluminium lamination.

Background technology

In integrated circuit (IC) manufacturing process, usually need be on device layer the arranging multiplayer conductive layer, to realize the connection between the device.

In some IC manufacturing process, use aluminium (Al) usually as conductive.In the technology of growth Al layer, the deelectric transferred ability of the Al that low temperature grows for a short time because the deelectric transferred ability of the Al that grows under the high temperature is compared is better, therefore, usually adopt high growth temperature method growth Al layer, to obtain deelectric transferred ability Al plate preferably, guarantee to make the reliability and stability of IC plate.

Referring to Fig. 1, Fig. 1 is the equipment schematic diagram of existing growth Al layer.Among Fig. 1, in the plasma reaction chamber 10, the wafer 11 of the Al layer of waiting to grow is placed on the temperature control heater 12; The Al that is positioned at wafer 11 tops makes on the target 13 and is applied with DC electric field, and electric field energy is higher usually; Be used to produce isoionic gas raw material such as inert gas argon (Ar), be injected in the chamber 10 by the perforate 14 on 10 sidewalls of plasma reaction chamber; In addition, gas is discharged from by perforate 15.In the vacuum environment in plasma reaction chamber 10, gas produces plasma under the high-energy electric field.The Al material that the plasma bombardment target obtains is deposited on crystal column surface, generates the Al layer.

For preventing that the signal between the conductive layer from disturbing, and also need add insulating medium layer usually between conductive layer.The high integration that IC makes makes to become tediously long and difficult at the small process last layer one deck ground growth conductive layer or the technical process of insulating barrier.

Be commonly used for the MIM plate of electric capacity,, be used in the IC manufacturing, to simplify manufacture process because of the layer structure of himself and the similitude of IC manufacturing process.Following brief description MIM layer structure.

Referring to Fig. 2, Fig. 2 is the structural representation of MIM plate.Among Fig. 2, the MIM plate mainly comprises three parts: conductive layer 20, insulating medium layer 21 and conductive layer 22.Wherein, insulating medium layer 21 materials can be silica (SiO ₂), the composition of conductive layer 20 and conductive layer 22 is identical usually.Referring to Fig. 3, Fig. 3 is the structural representation of conductive layer in the MIM plate.With conductive layer 20 is example, and Fig. 3 illustrates, and conductive layer 20 can be divided into three layers again, i.e. folder layer of metal aluminium in the double layer of metal nitride.

And, in view of the long Al method of high temperature in the existing IC manufacturing process, when making the MIM plate, also adopting the long Al method growth of high temperature Al layer usually, the growth device therefor can be referring to Fig. 1.

No matter at the Al growth technique of IC manufacturing or at the Al of MIM plate growth technique, all adopt the long Al method growth of high temperature Al layer.In Fig. 1, temperature control heater 12 need provide temperature up to 270 ℃ for the Al layer growth.And the Al crystal grain that grows under the high temperature is bigger usually, the Al layer thickness inequality that grows, and the phenomenon of surface irregularity is serious, thus the Al layer that requirement grows is thicker, with the irregular defective in reduction top layer.Referring to Fig. 4, Fig. 4 is the tangent plane schematic diagram of Al layer on the direction of growth that grows under the high temperature, the Al layer average thickness that grows 1300 dusts (

) about, and the thickness difference of Al layer thicker part and thin location 472 dusts (

) about, reaching the nearly 1/3rd of whole Al depth, evenness is relatively poor.

The surface irregularity of Al layer may not be very big to the influence of MIM electric capacity, but can influence the performance of making the IC plate.Because in the IC manufacturing process, be usually directed to the etching process on the material layer, exposing needed insulating medium layer of manufacturing process or Al layer, and the surface irregularity of Al layer may cause the problem that etching is excessive or etching is not enough, as, expectation exposes the insulating medium layer on Al layer upper strata by etching, but because the out-of-flatness of Al laminar surface, part A l material may embed the upper strata insulating medium layer, thereby can cause exposing on the etched surface conductive layer, the reliability of IC plate is made in influence; Similarly, if expectation exposes Al layer under the insulating medium layer by etching, but because Al laminar surface out-of-flatness, SI semi-insulation dielectric layer material may sink to the Al aspect, thereby make this part etch-stop stay insulating medium layer, cause making and occur service interruption or the excessive phenomenon of power consumption on the IC plate.

Therefore, the growth technique of existing Al layer is still needed and will be improved.

Summary of the invention

The object of the present invention is to provide a kind of growing method of aluminium lamination, make the Al laminar surface that grows smooth, thickness is even.

A kind of growing method of aluminium lamination, this aluminium lamination is applied in the MIM plate, the MIM plate is folder one deck insulating medium layer in the two conductive layers, and the making of described conductive layer comprises: be lower than 270 ℃ and be higher than under the ambient temperature of zero degree in temperature, growth is used to make the aluminium Al layer of conductive layer;

Be lower than 270 ℃ and be higher than that the described Al layer of growth further comprises under the ambient temperature of zero degree in temperature:

To being used to provide the target of the required Al material of Al layer growth, the isoionic gas flow that will be used to generate the described target of bombardment is controlled at more than or equal to 50 milliliters/second and is less than or equal in the scope of 70 milliliters/second.

Preferably, described ambient temperature is greater than zero degree, and is less than or equal to 150 ℃.

Preferably, described ambient temperature is more than or equal to 50 ℃, and is less than or equal to 60 ℃.

Preferably, be lower than 270 ℃ and be higher than that the described Al layer of growth further comprises under the ambient temperature of zero degree in temperature:

To being used to provide the target of the required Al material of Al layer growth, the dc electric power that applies on the described target is controlled at is less than or equal to 10 kilowatts more than or equal in 4 kilowatts the scope.

The present invention also aims to provide a kind of MIM plate, the Al laminar surface in the conductive layer is smooth and thickness is even.

A kind of MIM plate comprises: folder one deck insulating medium layer in the two conductive layers, the Al layer in the described conductive layer is lower than 270 ℃ and be higher than under the ambient temperature of zero degree and generate in temperature.

In the concrete enforcement of the present invention, by the Al layer of growth in the conductive layer under the low temperature environment temperature, the Al laminar surface that the Al layer that grows is compared grow under the hot environment is more smooth and thickness is even, is applicable to the environment of the microminiaturization process that IC makes.And because than long Al under the low environment, make that the process for making of Al is simple on IC or the MIM plate.

Description of drawings

Fig. 1 is the equipment schematic diagram of existing growth Al layer;

Fig. 2 is the structural representation of existing MIM plate;

Fig. 3 is the structural representation of conductive layer in the existing MIM plate;

Fig. 4 is the tangent plane schematic diagram of Al layer on the direction of growth that grows under the existing high temperature;

Fig. 5 is the profile of Al layer on the direction of growth that grows at low temperatures in the example of the present invention.

Embodiment

Al material layer for acquisition has stronger deelectric transferred ability in the IC manufacturing process, by the long Al method of high temperature, grows deelectric transferred ability stronger Al layer relatively under hot environment, correspondingly, the Al layer that grows is than out-of-flatness.But under some scenes, need to consider emphatically the evenness of the Al layer that grows, and the size of less important its deelectric transferred ability of consideration.Scene as, for the MIM plate, because its unique conductive coating structure, promptly between Al layer and insulating medium layer, also exist one deck can prevent that the barrier layer of Al migration from being metal nitride layer, therefore, in fact, for the MIM plate that has the barrier layer, its manufacture process can not need to consider how to improve the deelectric transferred ability of Al.

The present inventor breaks through the traditional method of the long Al of high temperature, considers growth Al layer under low temperature environment, and the inventor based on each experimental result, determines that the Al layer that grows at low temperatures is more smooth relatively by experiment repeatedly, and thickness is even.IC for high integration makes, and based on the uniform characteristics of Al layer thickness, can reduce the growth thickness of Al layer, helps to make the microminiaturization of IC.

For making technical scheme of the present invention and advantage clearer, describe in further detail below in conjunction with accompanying drawing.

The equipment schematic diagram of growth Al layer can be referring to Fig. 1 in the specific embodiments of the invention, and the temperature control heater 12 that is positioned at wafer 21 belows is controlled at the growing environment temperature of Al layer below 270 ℃, particularly, in the present embodiment, the ambient temperature of temperature control heater 12 control Al growths is between 50 ℃ to 60 ℃.In the practical application, also growth temperature can be arranged on lower, as about 25 ℃ room temperature.

In the present embodiment, based on the low-temperature epitaxy environment, the Al layer thickness that grows is even and the top layer is more smooth.Referring to Fig. 5, Fig. 5 is the profile of Al layer on the direction of growth that grows at low temperatures in the example of the present invention.Wherein, the Al layer average thickness that grows exists

About, the thickness difference of Al layer thicker part and thin location is

About, 1/10th of not enough whole Al depth, evenness is better.

In addition, in the present embodiment,, two links among Fig. 1 have been done improvement, having comprised: increased the Ar gas blowing and advance the speed in plasma reaction chamber 10, and reduce the DC electric field energy on the target for optimizing the growth of Al.

Particularly, in the existing Al layer growth technology, the injection rate of Ar gas is usually at 45 milliliters/second (sccm), and in the present embodiment, the injection rate of Ar gas is at 65sccm.The increase of Ar gas blowing speed can improve the uniformity of the plasma distribution that is inspired in the plasma reaction chamber 10, correspondingly, can make the deposition rate of Al on wafer balanced, helps the even growth of Al layer.In the practical application, the injection rate control of Ar gas can be helped in the scope of the even growth of Al layer, this scope comprises more than or equal to 50sccm and is less than or equal to 70sccm.

In the existing Al layer growth technology, the electric field energy that applies on the target is usually up to 22 kilowatts.And higher electric field energy can be accelerated the etching of plasma to target, the corresponding growth rate that can improve the Al layer.But too fast growth rate causes the inhomogeneous of Al layer growth easily.Therefore, in the present embodiment, the electric field energy that applies on the target is controlled at 10KW, suitably reduces the growth rate of Al.In the practical application, electric field energy on the target can be controlled at and help the Al layer evenly in the scope of growth, this scope comprises and is less than or equal to 10KW and more than or equal to 4KW.

Need to prove the ambient temperature at the place of still growing that the growth uniformity of Al is played a major role.

Adopt the electrology characteristic of the MIM plate that the long Al method of low temperature provided by the invention makes below by contrast, and the electrology characteristic of the MIM plate made of the long Al method of existing high temperature, the advantage of the long Al of embodiment low temperature.

For guaranteeing the reliability of IC plate, can require the MIM plate to have higher puncture voltage.The inventor is by gathering experimental data, the puncture voltage height of the MIM plate that the puncture voltage that draws the MIM plate that the long Al method of low temperature makes is made than the long Al method of high temperature.The MIM plate that the long Al method of abbreviation low temperature is made is a low temperature MIM plate, and the MIM plate that the long Al method of high temperature is made is a high temperature MIM plate.Referring to table 1, table 1 is listed the puncture voltage median of a plurality of MIM plates.Wherein, median embodies the statistical value of sampling.

The MIM plate	The puncture voltage median
		High temperature MIM plate	24.1500
High temperature MIM plate	25.3737
		Low temperature MIM plate	30.1050

Table 1

Find out that by table 1 data the puncture voltage of high temperature MIM plate is about 25 volts (V), and puncture voltage surpasses 30V on the low temperature MIM plate, the puncture voltage of low temperature MIM plate, the puncture voltage of the high temperature MIM plate of comparing exceeds nearly 20 percentage points.These data show, adopt low temperature MIM plate, compare and adopt high temperature MIM plate to make IC, help to improve the reliability of making IC more.

In addition, the MIM plate for as electric capacity requires electric capacity the smaller the better with the variation of voltage usually.Relation between electric capacity and the voltage shows as the quadratic function that electric capacity is voltage, and then the quadratic term coefficient is more little, represents that then electric capacity is stable more with the variation of voltage.In an instantiation, for low temperature MIM plate, in the variation relation of electric capacity with voltage, the quadratic term coefficient is 3 * 10 on it ^-5And for high temperature MIM plate, in the variation relation of electric capacity with voltage, the quadratic term coefficient is 4 * 10 on it ^-5Say that recently on the low temperature MIM plate, electric capacity is more stable with the variation of voltage mutually, correspondingly, the stability of making IC is better relatively.

In addition, the present invention also provides a kind of MIM plate, and particularly, in the conductive layer of this MIM plate, the Al layer grows up under above-mentioned low temperature environment temperature.

In sum, in the concrete enforcement of the present invention, by the Al layer of growth in the conductive layer under the low temperature environment temperature, the Al laminar surface that the Al layer that grows is compared grow under the hot environment is more smooth and thickness is even, is applicable to the environment of the microminiaturization process that IC makes.And because than long Al under the low environment, make that the process for making of Al is simple on IC or the MIM plate.

Claims

1. the growing method of an aluminium lamination is characterized in that, this aluminium lamination is applied in the MIM plate, and the MIM plate is folder one deck insulating medium layer in the two conductive layers, and the making of described conductive layer comprises:

Be lower than 270 ℃ and be higher than under the ambient temperature of zero degree in temperature, growth is used to make the aluminium Al layer of conductive layer;

2. method according to claim 1 is characterized in that, described ambient temperature is less than or equal to 150 ℃.

3. method according to claim 2 is characterized in that, described ambient temperature is more than or equal to 50 ℃, and is less than or equal to 60 ℃.

4. according to each described method in the claim 1 to 3, it is characterized in that, be lower than 270 ℃ and be higher than that the described Al layer of growth further comprises under the ambient temperature of zero degree in temperature:

5. MIM plate that utilizes the described method of claim 1 to obtain comprises: folder one deck insulating medium layer in the two conductive layers is characterized in that the Al layer in the described conductive layer is lower than 270 ℃ and be higher than under the ambient temperature of zero degree and generate in temperature.