JPS605537A - Semiconductor device - Google Patents

Abstract

PURPOSE:To enable to correct the characteristic of a semiconductor resistance element by employing as an external lead electrode for monitoring the characteristics a silicon layer, thereby readily monitoring the characteristics. CONSTITUTION:A polycrystalline silicon layer 7 is formed on an oxidized film 1, the layer 7 is selectively removed to form a resistance element having a terminal, and the element is then covered by thermal oxidation with an oxidized film. Then, the oxidized film covered on the both terminals 12, 13 of the element is selectively removed, high density boron atoms are diffused in the terminals 11, 12, and again covered as a high-doped low resistance region with the oxidized film. Then, the oxidized film covered on the region 14 except the region in which high density boron atoms are diffused, i.e., the body of the resistance element is selectively removed, the boron atoms of the amount controlled to obtain desired resistance value is accurately implanted by an ion implanting method on the region 14, and again covered with the oxidized film, thereby obtaining a monitoring resistance element.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a semiconductor device, and more particularly to an integrated circuit device equipped with a resistor element having electrode terminals for monitoring characteristics.

In a semiconductor integrated circuit device, an I and an extra semiconductor element are usually provided for monitoring the characteristics of the semiconductor element within the device. It is desirable that the dimensions and 4R structure of the element for characteristic monitoring such as C be the same as the element to be monitored, but due to the recent drastic miniaturization of each element in semiconductor integrated circuits, it is difficult to place the probe of the measuring device on the element surface. It is no longer possible to apply it directly. Therefore, monitoring of device characteristics in conventional integrated circuit devices is carried out either by (1) external lead-out electrodes formed on auxiliary elements of the same size, or (2) by auxiliary elements of large size that have a characteristic correlation with the monitored element. They also used elements. The latter method (2) is complicated and inaccurate because it requires calculating and evaluating the characteristics of the device under test based on data obtained from a large auxiliary device. Although the former method (1) allows the characteristics of the monitored element to be quickly determined with high precision, the characteristics of the element cannot be corrected to desired values.

This is because the aluminum used for the external lead-out electrode cannot withstand the treatment required to modify the device characteristics.

Polycrystalline silicon layers are widely used in semiconductor integrated circuit devices. For example, as a gate electrode in an insulated gate field effect transistor, and as an electrode of a diffused impurity source and its diffusion layer in a bipolar transistor.
Furthermore, in passive elements, it has been used as a resistor element. However, the characteristics of these semiconductor devices using polycrystalline silicon films cannot be determined until after the metal electrode for leading to the outside is formed, and it is impossible to modify the characteristics at this stage as described above, so the desired characteristics cannot be determined. This made the production of semiconductor devices unnecessary.

Therefore, one of the objects of the present invention is to provide a semiconductor device 1a in which element characteristics can be easily monitored and corrected.
There it is.

Another object of the present invention is to provide a semiconductor integrated circuit device equipped with a semiconductor element having an external lead-out electrode for monitoring that can withstand modification processing of semiconductor element characteristics.

According to the present invention, there is obtained a semiconductor device characterized in that a silicon layer is used as an external lead-out electrode for monitoring the characteristics of a semiconductor resistor element included in a semiconductor integrated circuit device. The silicon external j9 output electrode is connected to a monitoring semiconductor element formed on a semiconductor substrate of a semiconductor integrated circuit device, and extends an insulating layer covering the semiconductor substrate to an area outside the monitoring area. are doing. The monitoring element may be provided in addition to the elements making up the integrated circuit, or one of the integrated circuit components may be used. Preferably, the dimensions and structure of the monitor are the same as those of the device to be monitored. According to the invention, the probe of the measuring instrument is brought into contact with the externally led silicon electrode in order to measure the characteristics of the monitoring element and thereby learn the characteristics of the monitoring element. If the determined characteristics have not reached the desired values, the semiconductor device undergoes additional processing, such as heat treatment or re-doping of impurities, to bring the properties to the desired values. Then, the characteristics are checked again by touching the silicon electrode of the monitoring element with the probe. After that, if necessary, metal electrodes or metal wiring layers are added to the semiconductor device. is formed.

According to the present invention, since silicon that can withstand the high temperatures of the sex correction treatment is used for the monitor terminal electrode,
Characteristics can be easily and accurately monitored and modified. Furthermore, a master conductor device with metal electrodes or metal wiring layers can be manufactured after both monitoring and characteristic modification steps are performed.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

1A to 1G show embodiments of the resistor element of the present invention.

1A to 1F show cross sections through each manufacturing process, and FIG. 1 G1 is a plan view. Figure 1 F is Y − of Figure 1 G
This corresponds to a cross section along Y'. First, the semiconductor substrate 2 is thermally oxidized and covered with an oxide film 1 (FIG. 1A).

Next, polycrystalline silicon E7 is generated on the oxidized wAl by thermal decomposition of monosilane, and after selectively removing the polycrystalline silicon layer 7 to form a resistor element with a terminal portion, this polycrystalline silicon E7 is formed by thermal oxidation. The resistor element is covered with an oxide film (FIG. 1B). Referring also to FIG. 1G, the terminal portions 12 and 13 are connected to both ends of the main body 14 of the resistive element, and wide-area pad portions 12' and 13 extend over the oxide film l and serve as monitor terminal electrodes. Each ends with '.

Next, both terminal portions 12 and 13 (1
2' and 13') is selectively removed (FIG. 1C). Next, a high concentration of WI atoms is diffused into both terminal portions 12 and 13 of the resistor element from which the silicon oxide film has been removed to form a highly doped low resistance region. Then, it is covered again with an oxide film (FIG. 1D). Next, the oxide film covering the region 14 other than the region where the high concentration boron atoms have been diffused, that is, the main body of the resistor element, is selectively removed. Boron atoms controlled so as to be obtained are implanted with high accuracy by ion implantation, and then the oxide film is formed again (No. 111aF).

The pad portions 12' and 13' of the resistor element terminals are exposed and the probe of the measuring device is applied thereto to measure the resistance I of this monitoring resistor element. If the resistance value is found to be lower than the current value, the thickness of the silicon layer in the main body 14 of the monitor resistor and other resistors formed on the same oxide film 1 in the same process at the same time as the fabrication of the monitor resistor. The thickness of the silicon layer of the body is reduced to increase the resistance value. If the resistance value is higher than the desired value, further impurities are introduced into these resistors to lower the resistance value.

FIG. 2 shows a cross-sectional view of a further improvement of the above embodiment. The silicon main body part 9 and the terminal parts 20 and 20' of the monitor resistor (the same applies to the circuit resistance example) are buried in the silicon oxide film 18. This oxide film 18 is formed by selectively thermally oxidizing the silicon layer instead of selectively removing it. This structure flattens the surface of the semiconductor device.

The monitoring resistor of the embodiment described above may be used as a circuit element constituting an integrated circuit. In that case, the lead-out silicon electrodes 12, 13, 20, 20' are connected to other elements by wiring layers such as aluminum. When used only for characteristic monitoring, these derived silicon electrodes may be left as they are after use (after measurement is completed), but after use they should be removed by means such as etching or converted into oxides by oxidation. It is also possible.

Although the embodiments have been described above, the main part of the present invention is the characteristic monitoring electrode made of a silicon thin film that is in contact with the entire surface of the semiconductor substrate and extends outside the semiconductor region where the device is formed. The effect of the present invention is that the terminal is provided.
The characteristics of the semiconductor element can be measured before forming the metal electrodes, and therefore the characteristics of the element actually used can be positively controlled. Therefore, the technical scope of the present invention is 1
The invention is not limited to the embodiments described above, and the rights to this invention extend to all devices shown in the claims.

[Brief explanation of the drawing]

1A to 1F are cross-sectional views showing each manufacturing process of a monitor resistor according to an embodiment of the present invention, and FIG. 1G is a plan view thereof. The 11th straw IF corresponds to the cross section along YY' in FIG. 1G. FIG. 2 shows the location of another monitor resistor according to the present invention.
shows. 1.18...Silicon oxide film, 2...
Silicon substrate, 2...Contact region, 7...
...Polycrystalline silicon layer, 12.13.20.20'
...Terminal, 12'13'...Pad section, 14, I9...Resistor. Agent Patent Attorney Uchihara ” 20th

Claims (1)

[Claims] In a semiconductor device ζ including a plurality of semiconductor elements, the semiconductor element has a resistor element, and the resistor element has a high resistance region made of a silicon thin film on an insulating film and a high resistance region at both ends of the high resistance region. 1. A semiconductor device comprising a characteristic monitoring electrode terminal made of a silicon thin film connected to the insulating film and extending over the insulating film.