JPH04120731A - Apparatus for semiconductor treatment - Google Patents

Abstract

PURPOSE:To enable a lower-temperature processing for gate oxide formation and for a reflow of insulating film by passing vaporized liquid with carrier gas over an objective area of a semiconductor device while heating the device. CONSTITUTION:H2O gas is charged in an electric furnace 7 with N2 as carrier gas introduced through a line 2. If a thick film is to be formed on the surface, O2 is used as carrier gas. The sintering temperature is set at 350-450 deg.C, and the film thickness depends on the temperature. A film (1mum thick) is formed by sputtering Al-1%Si using a magnetron to determine the temperature dependency of film thickness. The results are 280Angstrom at 350 deg.C and 3300Angstrom at 450 deg.C, respectively, under the total flow rate of 1 liter/min and the reaction time of 60min. With a constant temperature of 400 deg.C, the film thickness varies nearly proportionally with the square of the reaction time. To form a dense coating, high temperature is required, preferably 420-450 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a processing apparatus for semiconductor devices. In particular, the present invention provides an apparatus for forming a gate oxide film in a semiconductor device, a reflow apparatus for an interlayer insulating film in a semiconductor device,
The present invention relates to an apparatus for sintering Al wiring in semiconductor devices.

[Prior art]

Thermal oxidation is widely used to form gate oxide films in semiconductor devices;
The difficulty is that it is subject to the thermal history before and after. As a countermeasure to this problem, pyrogenic (wet) synthesis, which oxidizes R2O using H2 and 02 in a furnace, is available.
oxidation), but it still requires a temperature of 700°C or higher.

In addition, techniques for depositing SiO2 films by CVD, sputtering, EB evaporation, ECR, etc. have been introduced.
Although this method does not undergo thermal history, the interface state is unstable, and it is far from practical use.

On the other hand, reflow of an interlayer insulating film in a semiconductor device is considered important as a countermeasure against an increase in the aspect ratio of a contact hole portion and disconnection of an Al wiring due to an increase in the density of devices.

And interlayer II! For the reflow of the edge layer, PSG (phosphorus-doped silicate glass) is used as the material for the interlayer insulating film.
12O0°C when using, 900°C when using BPSG (silicate glass doped with boron and phosphorus)
This requires a high temperature, and as a countermeasure for lowering the temperature, 5 solid state technology,
Japanese board, October 1987, page 41, Rapid Isothermal Fusi in steam
.

n has been introduced, but the technology of using ultrasound is not known. In addition, as a countermeasure against metallization failure in semiconductor devices, the Showa Society of Applied Physics proposed that coating tungsten over Al wiring suppresses stress migration of Al wiring and Al/Si wiring and improves reliability. This method was published in Autumn 1962 Proceedings 18a-Q-2 and 29P-V-], 1, but such a method is not preferable because it increases the number of processing steps.

Another countermeasure is to
The Institute of Electronics and Communication Engineers technical research report, R8, found that the lifespan was doubled by forming an oxide film through plasma treatment.
4-35 (pages 1 to 6). However, this method is still insufficient in film thickness necessary to prevent surface migration, is easily affected by the surface condition of Al, and lacks reproducibility and stability. As another countermeasure, after activating the surface with Ar plasma,
There is also a method of forming an oxide film at 400,018 degrees Celsius by immersing it in hot water at 0 degrees Celsius, but this deteriorates the wire bonding characteristics and contact characteristics, and the alumina film formed is a porous film, making it difficult to prevent after-corrosion. The disadvantage is that it is not.

〔the purpose〕

An object of the present invention is to achieve lower temperature processing in the formation of gate oxide films and reflow of interlayer insulating films by using the apparatus of the present invention.

Further, another object of the present invention is to provide, by using the device of the present invention,
The purpose is to reduce metallization failures in the wiring of 80-ohm alloys.

〔composition〕

A first aspect of the present invention provides a means for vaporizing and/or atomizing a liquid using ultrasonic waves, a carrier gas introduction means, a means for transporting the vaporized and/or atomized liquid through a processing region by means of a carrier gas, and a means for transporting the vaporized and/or atomized liquid through a processing region. The present invention relates to a single-conductor device processing apparatus comprising a semiconductor device holding means provided and a means for heating the semiconductor device holding area.

The second invention provides liquid R2O vaporization and/or
or a means for atomizing, a means for introducing oxygen as a carrier gas, a means for transporting the vaporized and/or atomized H2C through the processing region using oxygen gas, and a semiconductor device for forming a gate oxide film provided in the processing region. An apparatus for forming a gate oxide film in a semiconductor device, comprising means for holding the semiconductor device, means for heating the region for holding the semiconductor device, and means for supplying an alkali ion scavenger to the region as necessary. .

The third aspect of the present invention provides a means for vaporizing and/or atomizing liquid H2O by ultrasonic waves, a means for introducing oxygen as a carrier gas, and a means for transporting the vaporized and/or exposed H2C through a processing region using oxygen gas. , a semiconductor device comprising means for holding an interlayer insulating film-coated semiconductor device provided in a processing region, means for heating said holding region, and means for supplying an alkali ion scavenger to said region as necessary. The third aspect of the present invention relates to a reflow apparatus for an interlayer insulating film in a device.
Alternatively, a semiconductor device comprising means for transporting atomized H2C through a processing region, means for holding a semiconductor device with Al wiring provided in the processing region, and means for heating the semiconductor device holding region. The present invention relates to a sintering device for AR wiring in devices.

An example of the semiconductor device processing apparatus of the present invention is shown in FIG.

In Figure 1, 1 and 2 are carrier gas introduction lines, 3
is an ultrasonic vibrator, 4 is liquid water, 5 is a container for supplying an alkali ion scavenger, 6 is a holder for a semiconductor device, 7 is a furnace (electric furnace or lamp annealing device) serving as a processing area,
8 is a semiconductor device to be processed, and 9 is a flow control valve.

FIG. 2 is a cross-sectional view showing one example of a semiconductor device manufactured using the apparatus of the present invention. 11 is an insulating substrate, 12 is an active layer, 13 is a gate oxide film, 14 is a gate electrode, 15 is an interlayer insulating film, and 16 is an Al electrode.

For example, in the second invention, the apparatus shown in FIG. 1 is used to form the gate oxide film 13 shown in FIG.
The third aspect of the present invention is used for the reflow process, and the fourth aspect of the present invention is used for sintering the Al electrode 16.

The frequency of the ultrasonic transducer in the present invention is 20 kHz or more, preferably 85 Hz, which exceeds the cavitation generation range.
The frequency is 0 KHz or more, particularly preferably 1 to 2 MHz.

〔Example〕

Example 1 (Formation of Gate Oxide Film) Carrier gas 02 is introduced from carrier gas introduction line 2 at a rate of Iff/min. 3 uses megasonics of 1 to 2 MHz. 4 used ultrapure water.

A mixture of the gas generated by the megasonic and the 02 gas is introduced into the reactor 7, which is a processing area. The device 8 having the active layer 12 on the substrate 11 held by the holder 6 is heated to 950° C. or lower, and an oxidation reaction proceeds in the reactor 7 to form the gate oxide film 13. The film formation rate at this time depends on the temperature of the substrate 11.

When the temperature is 950℃, 26 people/minute When the temperature is 850℃, 7 people/minute When the temperature is 750℃, 3 people/minute It is.

Example 2 (Formation of gate oxide film using an alkali ion scavenger) An aqueous solution containing CQ- ions as an alkali ion scavenger such as Na ion as a contaminant in a container 5 and a semiconductor at the initial stage of the reaction. An aqueous solution containing F- ions having the ability to clean the surface of the material is introduced, and CD'' and F- are supplied to the gas components generated by megasonics, and an active layer 12 is formed on the substrate 11 in the reactor 7. Device 8 was processed.The ion concentration was 10-1 to 10-3 mol/Q for CQ- ions and 10-1 to 10-@mol/Q for QF- ions.

Other conditions were the same as in Example 1.

The film forming rate depended on the substrate temperature and was 7 persons/min at 800° C., which was 1° similar to that in Example 1.

Note that only one of CQ- and F- may be used, but the film forming rate at this time was 7.6 persons/min, which was somewhat fast.

Example 3 (Formation of gate oxide film using Q2 and other oxidizing gases) In Example 1, the film formation rate becomes very slow at temperatures below 700°C, so in order to increase the film formation speed, carrier gas introduction line 1 was used. An oxidizing gas such as NO□ was introduced at 11005 CC. In addition, in the container 5, No3- ion concentration 10-1 to 1
Used with 0-4 mol/Q aqueous solution, substrate temperature 65
The film was formed at 0°C. Note that all other conditions were the same as in Example 1.

The film formation rate was 120 people/hour at 650°C and 80 people/hour at 600°C.

In addition, the present invention can also be carried out under the same conditions as in Example 2 except for the above conditions.

Example 4 (Reflow of interlayer insulating film) Using the apparatus shown in Figure 1, the container No. 5 had an F- ion concentration of 1.
Add an aqueous solution of 0-2 to 5XIF7 mol/Q, and supply 02 from carrier gas introduction line 2 at a rate of 1Q/min.
It was carried out at a substrate temperature of 650 to 900°C. When the F- ion supply valve is closed, reflow will not occur unless the substrate temperature is 750°C or higher, but if F- ions are supplied,
Reflow was possible even at 650 to 750°C.

Improvement in step coverage was observed at both temperatures, whether PSG or BPSG was used as the interlayer insulating film.

Example 5 (Sintering of AI2 wiring) By sintering of Al wiring, dense aluminum oxide and aluminum hydroxide, ie /Ml, 03 and All, were formed on the surface of the ρ wiring.
A coating film consisting of 0(OH) is formed.

Al and AM and Al containing Si, Cu, Pd, Ti, etc.
Since sintering is performed after patterning the wiring layer made of the alloy, the total number of steps does not increase, and since the sintering of the present invention is a chemical reaction, it is easy to control the film thickness of the densified layer.

The device shown in Figure 1 is used, but the frequency of the ultrasonic transducer is 1.
~2 MHz was used. Reaction furnace 7 uses an electric furnace, and N2 is introduced from line 1 as a carrier gas.
O gas was introduced into the reactor 7. In particular, when the surface layer is a thick film, 02 is used as the carrier gas.

The sintering temperature is 350°C to 450°C.

The thickness of the formed film is 1 μm when AM-1% Si is sputtered using 6 magnetron sputtering, which depends on the temperature.
Tota Q, which determined the temperature dependence of the formed film thickness
Flow rate IQ/win, reaction time 60 minutes, 350°C 2
80 people, 3300 people at 450℃, and 400 people
Under a constant temperature condition of .degree. C., the dependence of film thickness on reaction time was approximately proportional to the 1/2 power of time.

Furthermore, during low-temperature formation, analysis results show that Al2O° vs. Al2
The ratio of AlO(OH) increases when the O(OH) ratio is formed at a high temperature, and high temperature formation is preferable for a dense coating film. Particularly preferred is 42O<0>C to 450<0>C.

From this, the coating film thickness can be controlled with sufficient precision in the range of 100 to 3,300 people by adjusting the reaction temperature, reaction time, and flow rate control valve.

〔effect〕

By using the apparatus of the present invention that uses ultrasonic waves, it was possible to perform the TPT gate insulating film formation and the reflow treatment of the interlayer insulating film at a lower temperature than before. Furthermore, by mixing various ions with the gas components generated by ultrasonic waves, a gate insulating film with good getter effects and interface conditions can be formed.
A highly reliable and high withstand voltage product was obtained. Another 600℃
Since the gate insulating film could be formed at a lower temperature, it became possible to use inexpensive borosilicate glass instead of a quartz substrate, making it possible to create low-cost devices (comparison of substrate types:
/3, so the cost of the device is also about 173. )
.

Furthermore, the sintering process of the AI2 wiring according to the present invention does not increase the number of processing steps, and since the process is a chemical reaction, it is easy to control the thickness of the surface film.

In order to compare the average failure time of a semiconductor device coated by the sintering process of the present invention with a semiconductor device without a coat, the following accelerated test was conducted.

The coating thickness is 400 when formed at 42O℃ and 400 when formed at 450℃.
It's a person. Substrate temperature 125℃, current density IX]O'A/
d, step is polysilicon gate film thickness, pattern W/L
= 1 .mu.m/4000 .mu.m, the MTTF (mean time to failure) was 400 hours, 8 times as much as that without coating when formed at 420.degree. C., and 480 hours when formed at 450.degree. C., an improvement of nearly one digit. Furthermore, with this thinness, no wire bond defects occurred in the next process.

This has made highly reliable wiring processing possible.

[Brief explanation of drawings]

FIG. 1 shows a specific example of the apparatus of the present invention, and FIG. 2 is a sectional view showing an example of a semiconductor device processed by the apparatus of the present invention. 1...Carrier gas inlet 2...Carrier gas inlet 3...Ultrasonic vibrator 4...Liquid (atomized component) 5...Liquid for adding various ions 6...Sample holder and/or or internal heater 7.
... Heater 8 ... Sample 9 ... Flow rate control valve 11 ... Insulating substrate 12 ... Active layer 13 ... Gate oxide film 14 ... Gate electrode 15 ... Interlayer insulation film! Figure 2? \-5

Claims (1)

[Claims] 1. Means for vaporizing and/or atomizing a liquid using ultrasonic waves, means for introducing a carrier gas, means for transporting the vaporized and/or atomized liquid through a processing region by means of a carrier gas, and a means for transporting the vaporized and/or atomized liquid through a processing region. 1. A processing apparatus for a semiconductor device, comprising: a semiconductor device holding means provided in the semiconductor device holding area; and a means for heating the semiconductor device holding area. 2. Means for vaporizing and/or atomizing liquid H_2O by ultrasonic waves, means for introducing oxygen as a carrier gas, H_2O vaporized and/or atomized by oxygen gas.
means for transporting 2O through the processing region, means for holding a semiconductor device for gate oxide film formation provided in the processing region, means for heating the region holding the semiconductor device, and optionally applying an alkali to the region. 1. An apparatus for forming a gate oxide film in a semiconductor device, comprising means for supplying an ion scavenger. 3. Means for vaporizing and/or atomizing liquid H_2O by ultrasonic waves, means for introducing oxygen as a carrier gas, H_2O vaporized and/or atomized by oxygen gas.
Means for transporting 2O through a processing region, means for holding an interlayer insulating film coated semiconductor device provided in the processing region, means for heating the holding region, and means for supplying an alkali ion scavenger to the region as necessary. 1. A reflow apparatus for interlayer insulating films in semiconductor devices, characterized by the following: 4. A means for vaporizing and/or atomizing liquid H_2O by ultrasonic waves, a carrier gas introduction means, a means for transporting the vaporized and/or atomized H_2O through a processing region by a carrier gas, an Al provided in the processing region
An apparatus for sintering Al wiring in a semiconductor device, comprising means for holding a wired semiconductor device and means for heating the semiconductor device holding area.