JPS594031A - Manufacturing device of semiconductor - Google Patents

Abstract

PURPOSE:To obtain a semiconductor element in which adhesiveness with an oxide film or a CVD film of metallic wiring is improved and electrical characteristics do not degrade by constructing a means executing annealing treatment of a decompression type treating furnace receiving a semiconductor substrate, a means decompressing the inside of the furnace, a heating means and a means injecting a plural kinds of gases. CONSTITUTION:A decompression monitor 14 is set up to the decompression type treating furnace 11 communicated with a vacuum pump 13 as the decompression means, and the state of decompression by the pump 13 is adjusted so as to be kept constant. A jig 16 to which a large number of the semiconductor substrates 15a, 15b, etc. are errected is received into the furnace 11, and the outer circumference of the furnace 11 is surrounded by the resist heater 17. The nozzle rows 18a, 18b, etc. are each fitted to the upper section and lower section of the inside of the furnace 11, and an atmospheric gas divided by a manifold 20 is ejected through transfer pipes 19 from the nozzles. Opening and closing valves 21 in numbers corresponding to the kinds of the gases and flowmeters 22 are set up to the transfer pipes 19, and the gas of N2 or H2 or the like is poured. Accordingly, a hydroxide corrosion between a metallic layer and the oxide film is prevented.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to annealing treatment that is part of the manufacturing process of semiconductor integrated circuits, etc., and is a means for stabilizing wiring formed within a semiconductor substrate. The present invention relates to a semiconductor manufacturing device that has been improved.

[Technical background of the invention]

Semiconductor devices are generally manufactured based on a plenary technique in which P-type or N-type impurities are added using an insulating oxide film formed on a semiconductor substrate as a mask. If this semiconductor device constitutes a TJ circuit, such as an active element such as a diode or a transistor,
For wiring, it is sufficient to simply draw out lead wires from the electrodes of each semiconductor element within the substrate, and there are many uses for a device having such a configuration. However, on the other hand, the power handled is relatively small, and in addition to active elements, passive elements such as resistors and capacitors are included, and the combination of these elements is mainly used to increase functionality, miniaturize, and reduce failure rates. Therefore, the semiconductor Q-, product circuit (I
OLSI, VT, SI, etc.) are being planned. To construct such a Kei integrated circuit, a semiconductor substrate P is required.
It is necessary to form a multilayer structure of circuit elements in the V, and to provide wiring to organically connect them. As integration becomes more sophisticated, wiring metals such as aluminum must also be made thinner. However, in this case, if sufficient adhesion is not achieved in the wiring, variations will occur in the electrical characteristics of the manufactured semiconductor integrated circuits. Therefore, it becomes impossible to expect the expected behavior from these. Therefore, a baking process is performed to firmly adhere the wiring metal to the board.

The process up to this annealing treatment will be explained below using an example using a silicon semiconductor substrate.

First, the surface of the semiconductor substrate is oxidized to form an oxide film (S+C).
) to form. Next, using this oxide film (8+O,) as a mask, P-type or N-type impurities are selectively diffused into the entire substrate to form a multilayer structure of active elements, 11 elements, and passive elements.

The above-mentioned oxide ll5 (S i O,:) or OV I) such as a phosphorus silicate glass (L'8G) film or a boron silicate glass (BSG) film formed as a diffusion source of impurities.
Since the collar is an insulating material, it can serve as a protective film for the electrical characteristics of each element and can be used for the next wiring. The wiring connects each element by depositing wiring metal on these oxide films or OVD films by vapor deposition or sputtering. A semiconductor integrated circuit is formed as described above using aluminum (AJ), an aluminum-silicon mixture (A l-S i ), an aluminum-silicon-copper mixture (A l-8i-Ou ), etc. as the wiring metal. do.

However, this alone is not sufficient to ensure the reliability of the circuit, so it is recommended to immerse the wiring metal and the contact surface of the oxide film (CV Make it.

Conventionally, this annealing process uses nitrogen (N,
) or hydrogen (FIt) atmosphere, 400-50
Annealing was carried out at a temperature of about 0° C., that is, at a temperature lower than the melting point of the wiring metal for several minutes to several tens of minutes.

[Problems with background technology]

However, when baking is carried out regularly as described above, it is difficult to completely remove the moisture (H2O) that has adhered to the inside of the wiring metal and to the underlying oxide film or OVD film. In other words, using aluminum (AI) as the wiring metal,
A semi-depleted body without water (1-120) being released! ＋、When a product circuit is manufactured, when it is operated by energizing it, the following electrochemical reaction is promoted, causing hydroxide corrosion (electrolytic corrosion) at the grain boundaries of aluminum (AJ). This will lead to a disconnection.

2H'+2 e--+H2, Aj""+3 (OH)-
+AJ (OH) 3 Ota, KI - Mamoru 1 flight phosphorus silicate glass (PSG) lI! When the concentration of phosphorus in It is high, the phosphorus pentoxide (phosphorus
P2O5) to 1) phosphoric acid (2H11PO4), which has the disadvantage of accelerating the reaction.

[Purpose of the invention]

This invention was made in order to solve the problem of melting point between the metal wiring and the oxide film or OV D B'.
It is an object of the present invention to provide a semiconductor manufacturing apparatus that reduces electrical property deterioration factors other than this adhesion during an annealing process that brings fi and p into close contact.

[Summary of the invention]

That is, in the semiconductor manufacturing apparatus according to the present invention, the annealing process is carried out in a reduced-pressure type processing furnace in which a reduced-pressure type gauze is used, and when the manufactured semiconductor device is operated, moisture that causes hydroxide corrosion at the grain boundaries is removed from the wiring metal, Or, if it is attached to an oxide film or a QVD film, it is made to separate from it.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows its construction, in which a reduced-pressure processing furnace 11 for annealing is communicated via a joint 12 with a reduced-pressure means, such as a vacuum pump 13. This processing furnace 11 is provided with a pressure reduction monitor 14 to adjust the pressure reduction state by the vacuum pump 13 to be constant. This reduced pressure treatment furnace 1
1 includes a large number of semiconductor substrates 15a, 15b...
A jig 16 is set up in which the processing furnace 11 is lined up, and a heating means, such as a resistance heater 17, for heating the inside of the processing furnace 11 is installed outside the processing furnace 11. Nozzle rows 18g and 18h are provided in the upper and lower parts of the processing furnace 11, respectively.
8s and 18b pass through a transfer pipe 19 and are properly connected to a manifold 20.
The gas forming the divided atmosphere is ejected from each of these parts. That is, this transfer pipe 19 is provided with a number of on-off valves 21 corresponding to the type of gas and an fM quantity meter 22 to supply an atmospheric gas such as nitrogen (N) or hydrogen (1).

When annealing is performed using such an apparatus, the semiconductor substrates 15a, 15b, . . . are arranged on a jig 16 and set in the processing furnace 11. Then, the vacuum pump is operated to reduce the pressure inside the processing furnace 11 to 01 to ITorri degrees. While maintaining this pressure state, heat the processing furnace 1 to 400 to 500°C using a resistance heater.
A gas of hydrogen (H, ) 2J or nitrogen (Nt) 24 is introduced into the semiconductor substrate 15a.

Burn for 15 hours...

In other words, if the pressure is reduced as described above, the moisture (H, 0) in the furnace 11 will easily evaporate due to the pressure, and not only will the joints of the wiring be tightly bonded to the alloy metal, but also the hydroxide Corrosion (electrolytic corrosion) can also be prevented.

The roasted sweet process performed in this way is IO.

It can be applied to any semiconductor substrate such as LSI, and the wiring junction material is aluminum (AI), aluminum-silicon mixture (AI!-8i), aluminum-silicon copper mixture (kl-8i-Ou), etc. An oxide film (8i0t) or an OVD film (PSG) is effective.

When we actually compared the polar type IO, it was found that the electrolytic corrosion defects caused by aluminum (AI) were certainly reduced compared to the conventional one.

Further, the atmospheric gas supplied to the decompression processing furnace 11 is, for example, oxygen (0,), ?, as shown in FIG. 5. Monosilane (
S i'H4) 26. and hydrogen phosphide (PH,)
, 27, a transfer pipe 19, an on-off valve 21, and a flow meter 22 may be additionally installed. In this case, the above gas is ejected while maintaining the reduced pressure state after annealing. This is to form a surface protective film on wiring metal such as aluminum. Therefore, moisture can be separated more completely, which helps prevent electrolytic corrosion defects.

〔Effect of the invention〕

As described above, according to the semiconductor manufacturing apparatus of the present invention, an alloy layer is formed on the bonding surface between the wiring metal and the oxide film size or OV It can also prevent hydroxide corrosion (electrical corrosion). For this reason, in semiconductor integrated circuits with thin wiring patterns, it is particularly effective compared to conventional methods, and stable 'Fl (comfortability) can be obtained, and product reliability can be improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a semiconductor manufacturing apparatus illustrating a further embodiment of the present invention, and FIG. 2 is a block diagram of another embodiment of the present invention. 11...Reduced pressure type processing furnace, 12...Joint, 13
... pressure reduction means (vacuum pump), 14 ... pressure reduction monitor, 15 ... semiconductor substrate, 16 ... jig (boat),
17... Heating means (resistance 4-ta), 18...
Nozzle row, 19... Transfer pipe, 20... Manifold,
21... Opening/closing valve, 22... Flow meter, 23... Hydrogen (H,), 24... Nitrogen (N,), 25... Oxygen (
0, ), 26... Monosilicane (SIH4), 27
...Hydrogen phosphide (PH3).

Claims (1)

[Claims] A reduced pressure processing furnace for accommodating a semiconductor substrate, a pressure reduction means for reducing the pressure inside the processing furnace, a heating means for heating the processing furnace, and a means for injecting a plurality of types of atmospheric gas into the processing furnace. A semiconductor manufacturing device characterized by: