JPH01233749A - Formation of active layer laminated device - Google Patents

Abstract

PURPOSE:To enhance a yield of device formation by a method wherein semiconductor elements for test use having a pad for measurement use are installed in individual active layers in order to confirm, at the individual active layers, a characteristic and an operation of semiconductor elements contained in the active layers. CONSTITUTION:A pad 7A has a sufficiently large area so that a measuring terminal of a memory apparatus used to measure a characteristic of a semiconductor element for test use can come into contact with it easily. The surface of a silicon oxide film 5 is flattened by a CVD method or the like. The film thickness of the oxide film 5 is adjusted so that the surface of the pad 7A is exposed during a flattening operation. The semiconductor element for test use having the pad 7A is formed in a first-layer active layer. The measuring terminal of the measuring apparatus can be easily brought into contact with the pad 7A. Accordingly, an operating characteristic of the semiconductor element for test use can be easily confirmed immediately after the active layer has been formed. In the same manner, the semiconductor element for test use having the pad is formed at individual active layers in a second-layer active layer and additional layers. By this setup, a yield of device formation can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for forming an active layer stacked device in which active layers including semiconductor elements are stacked.

[Conventional technology]

Conventionally, the following method has been used to create an active layer stacked device by stacking active layers including semiconductor elements. This will be explained below using the cross-sectional view of FIG.

First, a device in the first layer of the active layer is formed by the silicon substrate 1, the field oxide film 2, the gate electrode 3A each made of a polycrystalline silicon film, the intralayer arrangement 14A, the glabella wiring 6A, and the like. Furthermore, after forming a silicon oxide film 5A as a glabellar insulating film, the surface of the silicon oxide film 5A is planarized by an etch-back method or the like. Next, the silicon oxide film 5B as a four-layer insulating film that forms a device in the second layer of the active layer is formed by the island-shaped silicon film 8, the gate electrode 3B, the intralayer wiring 4B, the glabella wiring 6B, etc. As in the case of the first layer, the surface is planarized by an etch-back method or the like. After the third active layer, the second active layer
It is formed in the same way as the layer. Finally, wiring and pads 7 for measuring device terminals are formed of aluminum on the silicon oxide film 5C.

An active layer stack device is fabricated by the method described above. Such technology is introduced, for example, in the paper by Katsunori Mitsuhashi, etc., listed on page 251 of the Proceedings of the 4th New Functional Device Technology Symposium.

[Problem to be solved by the invention]

In the above-described conventional method for forming an active layer stacked device, pads for measurement terminals of a measuring device are created only during aluminum wiring formation, which is the final step of prototyping an active layer stacked device. For this reason, the operation of the semiconductor elements in each active layer could only be confirmed after the final step of prototyping.

Therefore, even if a semiconductor element in any active layer has poor device characteristics or fails to operate, no feedback can be applied to subsequent active layer formation, and device prototype fabrication continues. As a result, there are drawbacks such as poor device characteristics of the prototype active layer stacked device and a decrease in the yield of device formation.

[Means to solve the problem]

The method for forming an active layer stacked device of the present invention includes a test semiconductor having a pad for contacting a measurement terminal of a measuring device for measuring the characteristics of the semiconductor element when stacking active layers including a semiconductor element. A device is formed within each active layer.

〔Example〕

Hereinafter, the present invention will be explained using the drawings.

FIG. 1 is a perspective view of a test semiconductor device for explaining an embodiment of the present invention. In this embodiment, a polycrystalline silicon thin film is used as a semiconductor thin film, a silicon oxide film is used as an insulating film between the eyebrows, and a semiconductor substrate is used as a semiconductor substrate. A silicon substrate and a MOSFET are used as test semiconductor elements. The test semiconductor device is created at the same time as the prototype device is created.

First, selective oxidation is performed on a silicon substrate 1 to form a field oxide film 2 and perform element isolation.

Next, a gate electrode 3 made of polycrystalline silicon is formed, and then source/drain regions are formed by ion implantation of impurities or the like. Next, after the intralayer wiring 4 is formed of a polycrystalline silicon film, the glabella wiring and the pad 7A are formed of a polycrystalline silicon film. At this time, the pad 7A is made to have a sufficiently large area so that a measuring terminal of a measuring device for measuring the characteristics of the test semiconductor element can easily come into contact with the pad 7A. after that,
The surface of silicon oxide film 5 is planarized by CVD method or the like. During this flattening, the surface of the pad 7A is exposed.
Through zero or more steps of adjusting the thickness of the silicon oxide film 5, a test semiconductor element having the pad 7A in the first active layer is formed.

Since the pad 7A of the test semiconductor device can be easily contacted with the measurement terminal of the measurement device, the operating characteristics of the test semiconductor device can be easily checked immediately after the active layer is formed.

Test semiconductor elements having pads are similarly formed for each active layer in the second and subsequent active layers. As a result, devices can be fabricated by laminating active layers while checking the operation of the semiconductor element immediately after forming each active layer.

In the above embodiments, the semiconductor thin film is a polycrystalline silicon thin film, the interlayer insulating film is a silicon oxide film, the semiconductor substrate is a silicon substrate, and the test semiconductor element is an M
Although OSFET is used, it can also be applied to other semiconductor thin films, other glabella insulating films, other semiconductor substrates, and other semiconductor devices for testing. Further, as the material for the pad, it is desirable to use a semiconductor material or a high melting point metal that does not affect other semiconductor elements in subsequent steps.

〔Effect of the invention〕

As explained above, the present invention provides a test semiconductor element having a measurement pad for each active layer.
Immediately after forming each active layer in the active layer stacked device prototyping process, it is possible to check the characteristics and operation of the semiconductor element included in that active layer, and the results can be fed back to subsequent prototypes. Element characteristics and yield of device formation can be improved.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a test semiconductor device for explaining an embodiment of the present invention, and FIG. 2 is a sectional view of a conventional active layer stacked device. 1... Silicon substrate, 2... Field oxide film, 3
．． 3A, 3B, 3C...gate electrode, 4.4A. 4B, 4C... In-layer wiring, 5.5A, 5B, 5C...
・Silicon oxide film, 6A, 6B, 6C...interlayer wiring,
7.7A...pad, 8...island silicon film.

Claims (1)

[Claims] When stacking active layers containing semiconductor elements, a semiconductor element for testing is formed in each active layer, the semiconductor element having a pad for contacting a measurement terminal of a measurement device for measuring the characteristics of the semiconductor element. A method for forming an active layer stacked device.