JPS61144037A - Semiconductor device and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a device having good heat conductivity and crystallinity uniformly over a large area with a desirable yield, by providing a three-layer insulation film consisting of an insulation layer having a lower heat conductivity, a diamond layer and an adhesive layer while depositing these layers in that order from an element forming layer toward a substrate. CONSTITUTION:An insulation layer 14 of silicon dioxide for example is provided on the polished surface of an element forming layer by the CVD or spattering process at a temperature lower than the melting point of an adhesive 13. Further, a diamond layer 15 is formed thereon to 2mum thick by the glow discharge process for example. The diamond layer 15 is then bonded to a support substrate 17 of ceramics such as alumina nitride with an adhesive 16 of a epoxy or polyimide resin for example. The support substrate 17 is the removed by grinding or etching. Finally, the adhesive 16 is removed with an appropriate solvent. Thus, the diamond layer 15 provides good heat dissipating properties and the insulation film 14 assures that no impurity is included in the element forming layer 12.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a semiconductor device having an integrated circuit structure separated by a current-visitor, and a method for manufacturing the same.

- (Prior art) Conventionally, as this type of semiconductor device and its manufacturing method, single crystal silicon is epitaxially grown on an insulator such as sapphire (A40s) or spinel (MgAJt Oa), and elements are formed in the epitaxial layer. There is a semiconductor device formed therein. However, due to the poor single crystallinity of the silicon single crystal epitaxially grown on sapphire or spinel, a large leakage current flows at the interface between sapphire or spinel and silicon, resulting in unexpectedly high power consumption and the mobility of semiconductors. Since it is lower than that of a single crystal, it has the disadvantage that it does not reach the expected high speed, or that the yield is low because it uses heteroepitaxial growth, and it also has the disadvantage that high quality crystals cannot be obtained over a large area.

(Objectives of the Invention) The present invention aims to eliminate these drawbacks, and to obtain devices with good heat conduction and good crystallinity on an insulator uniformly over a large area with a high yield.

(Structure of the Invention) According to the present invention, in a semiconductor device in which a semiconductor element forming layer is provided on a supporting substrate via an insulating layer, the insulating layer has low thermal conductivity from the element forming layer toward the substrate. 111t in the order of the insulating layer diamond layer and the adhesive layer,
A semiconductor device characterized in that it includes three rrI4 layers is obtained.

Further, according to the present invention, after providing an element isolation region on a semiconductor single crystal substrate and forming an element in the semiconductor portion, the semiconductor device forming surface is adhered to a holding substrate with an adhesive, and the semiconductor single crystal substrate is attached from the back side. The layer on which the semiconductor device is formed is removed while being polished, and then an insulating film with low thermal conductivity is deposited on the removed surface at a temperature lower than the melting point of the adhesive, and then a diamond layer is formed on this layer. A method for manufacturing a semiconductor device is obtained, which comprises fixing the surface to a support substrate via an adhesive, and then removing the holding substrate.

Since the thermal tensile coefficient of diamond is close to 8i, there is little deformation of the device layer, and the thermal conductivity is about 4 times better than that of Si.
Using a diamond layer on the bottom surface of the device has the effect of improving the dissipation of heat generated in the device layer, and the insulating layer between the diamond layer and the device layer prevents impurities contained in the diamond layer from being introduced into the device layer. It has a preventive effect.

(Example) Next, an example of a semiconductor device and a method for manufacturing the same according to the present invention will be described based on drawings.

The case where silicon is used as the semiconductor will be described.

FIG. 1 shows a semiconductor device obtained by the present invention, and FIG. 2 shows a manufacturing method thereof.

From Figure 2(a) 1! Now, a method for obtaining the semiconductor device shown in FIG. 1 will be explained. A silicon dioxide (SfO,) film 2 is formed on the surface of a single-crystal silicon substrate 1, and then a desired region of the 8 ion film 2 is removed using a microfabrication technique such as photolithography, particularly dry etching. Using the remaining 8i01 film 2 as a mask, a groove 3 having a desired depth and vertical shape is formed in the substrate by dry etching as shown in FIG.

Since this groove becomes an isolation region for the elements, the finer the width of the isolation groove, the higher the degree of integration of the elements.

Next, the 8i02 film 2 used as the mask is removed, and silicon dioxide 2a and silicon nitride film 2b are again formed over the entire surface of the substrate. Such a diagram is shown in FIG. 2(b).

Next, polycrystalline silicon 4 is grown to a thickness equal to or greater than the depth of the isolation trench 3 using a vapor phase growth method, filling the isolation trench 3, and making the surface flat by a normal polishing method, etc., followed by silicon nitride film 2b. By using thermal oxidation as a mask,
Oxide film 2c is formed only on the surface of polycrystalline silicon 4 buried in the isolation trench.

Next, the device formation process begins. Following Fig. 2(C), groove 3
After removing the silicon nitride film 2b and oxide film 2a other than the part buried in the gate oxide film 5, a new gate oxide film 5 of a desired thickness is formed by thermal oxidation, and then a gate electrode 6 is formed using polycrystalline silicon. do.

Using the gate electrode 6 as a mask, a source region 7 and a drain region 8 are formed by ion implantation, and then an interlayer insulating film 9 such as phosphorus glass is deposited by CVD, and then a contact hole is formed. 2(d) is obtained, and an element of an MO8 integrated circuit can be formed. Next, the element forming surface and a holding substrate 12 such as a silicon wafer are bonded together with an adhesive 13 such as a resin such as polyimide. Then, the single-crystal silicon substrate 1 excluding the element forming surface is removed by mechanochemical boring.In the mechanochemical boring, organic ammonia is used as a colloidal silica chemical solution as abrasive grains, so that the separation groove 3 is covered. Since the processing speed of silicon dioxide 2a is considerably lower than that of single-crystal silicon at 1150 Hz or less, the boring process can be stopped at the depth of the groove, and the element forming surface can be easily left.Such a diagram is shown in FIG. Shown in e).

Next, an insulating film 14 such as silicon dioxide is formed on the polished surface of the element forming layer by CVD or sputtering at a temperature lower than the melting point of the adhesive 13, and then the diamond layer 15 is coated with an adhesive 16 such as epoxy or polyimide. The supporting substrate 17 is adhesively fixed to a ceramic substrate such as alumina nitride using resin, and then the holding substrate 12 is removed by polishing or etching. Finally, adhesive 16 is removed using a suitable solvent such as methylene chloride or trichloroethylene. In this way, the semiconductor device shown in FIG. 1 is obtained.

As explained above, according to the present invention, a semiconductor layer having good crystallinity can be easily formed on an insulator, heat dissipation is good due to the diamond layer 15, and elements are formed using the insulating film 14. Layer 12 is free of impurities.

Further, the thickness of the element forming layer can be freely changed by changing the depth of the separation groove.

In the embodiments, the formation of an MO8 integrated circuit is taken as an example, but other types of devices such as bipolar integrated circuits can be formed in the same manner. Furthermore, although a silicon substrate has been described in the embodiment, the present invention can also be applied to other semiconductor single crystal substrates such as gallium arsenide and indium phosphide.

Further, as the element isolation method, any method that isolates elements using an insulator, such as the LOCO8 method or a modification thereof, can be used.

(Effect of the invention) According to the present invention, the pest capacity is extremely small.
(5ilicon on In5ulator)
While maintaining the advantages of the structure, the diamond layer improves heat dissipation, especially the thermal conductivity when using a multilayer 80I, and the insulating film prevents impurities from entering the element layer. It is possible to improve the defects caused by poor crystallinity such as leakage current and mobility of the SOI structure of the SOI structure, reduce power consumption of the device, improve high-speed operation, and increase the yield of such devices in a large area. You can get a good deal.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an embodiment of the semiconductor device of the present invention (
a) to (f) are cross-sectional views for explaining the manufacturing method of the present invention. DESCRIPTION OF SYMBOLS 1... Single crystal silicon substrate, 2.2a, 2c... Silicon dioxide film, 2b... Silicon nitride film, 3... Groove, 4... Polycrystalline silicon, 5...
...Gate oxide film, 6...Gate electrode, 7...y
- source, 8... drain, 9... interlayer insulating film, 10...
... Aluminum wiring, 12... Holding substrate, 13... Adhesive, 14... Insulating film, 15... Diamond layer, 16... Adhesive, 17... Supporting substrate,

Claims (1)

[Claims] 1. In a semiconductor device in which a semiconductor element formation layer is provided on a supporting substrate via an insulating layer, an insulating layer having low thermal conductivity from the element formation layer toward the substrate as the insulating layer. A semiconductor device comprising three layers stacked in this order: a diamond layer and an adhesive layer. 2. After providing an element isolation region on a semiconductor single crystal substrate and forming an element in the semiconductor portion, the semiconductor device forming surface is bonded to a holding substrate with an adhesive, and the semiconductor single crystal substrate is removed while being polished from the back side. to leave the layer on which the semiconductor device was formed, and then deposit an insulating film with low thermal conductivity on the removed surface at a temperature lower than the melting point of the adhesive, form a diamond layer, and cover this surface with the adhesive. 1. A method of manufacturing a semiconductor device, which comprises fixing the semiconductor device to a support substrate via a support substrate, and then removing the holding substrate.