JPS61154142A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To form an effective element isolating region simply, by forming an isolating and insulating film from an insulating film on the first substrate, which is selectively formed, and a thermosetting insulating material between the insulating film 11, an epitaxial layer and the second substrate by heating, and isolating the epitaxial layer on the second substrate. CONSTITUTION:An insulating film 11 is formed on the entire upper surface of a p<-> type substrate 41. An insulating film 111 is made to remain. The other insulating film is etched. Then, an n<-> type epitaxial layer 32 is formed. Liquid glass 12 is uniformly applied on the selected epitaxial layer 32 and the insulating film 111. Then, another p<-> type substrate 42 is overlapped on te insulating film 111 and the n<-> type selected epitaxial layer 32 through the liquid glass 12. They are stuck together. The compound material is heat-treated. The side of the p<-> type substrate 41 is polished. The selected epitaxial layer 32 and an isolating an insulating film 10 are exposed. Then, an n<-> type region 20 is formed on a part of the n<-> type selected epitaxial layer 32.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a semiconductor device, and particularly to a method for manufacturing a semiconductor device that requires isolation between elements.

[Prior Art] FIG. 2 is a cross-sectional view showing the structure of a bipolar transistor manufactured from a wafer that has not undergone any processing by a conventional method. In the figure, an n+ type rough floating collector 5 is formed on a D-type substrate 4, and a p+ type region 6 is formed between these collectors on the substrate. An n- type epitaxial layer 31 is formed on the n+-type floating collector 5, and an n+-type region 2 is formed on a part of this epitaxial layer. Zarani, p.
An isolation insulating film 1, which is an oxide film, is formed on the 4-type region 6.

When a bipolar transistor is formed from a wafer that has not undergone any processing, the structure shown in the above figure is generally most often used to ensure a high isolation voltage. That is, when using the D-type substrate 4, the n-type region 2n-type epitaxial layer 31-n'' type floating collector 5-p+ type region 5-n+ type rough floating collector 5n-type epitaxial layer 31-n+ type Area 2
form an npn transistor with a lateral structure of p÷
By controlling the length of the shape region 6 and the p+ concentration, the mutual separation of the 01 shape regions 2 is substantially maintained.

[Problems to be Solved by the Invention] By the way, when manufacturing a semiconductor device with such a lateral structure from a conventional wafer that has not undergone any processing, when the isolation insulation l11 is made, the isolation insulation 1111 and n+
There is a problem in that defects occur due to stress at the interface between the rough floating collector 5p1 and the type region 6, resulting in conduction between the n+ type regions 2.

This invention was made in order to eliminate the drawbacks of the conventional devices as described above, and it provides a semiconductor that can easily create effective isolation for semiconductor devices such as bipolar transistors that require isolation between elements. [Means for Solving the Problems] A method for manufacturing a semiconductor device according to the present invention includes forming a predetermined area on a first W plate of a first conductivity type. selectively forming an insulating film through exposure, then forming a second conductivity type epitaxial layer on the exposed first substrate, and then providing a thermosetting insulating material on the insulating film and the epitaxial layer; Next, a 211th plate of the first conductivity type is layered on the insulating film and the epitaxial layer via the thermosetting insulating material, and then the composite is heated to form the epitaxial layer from the insulating film and the thermosetting insulating material. Then, the first substrate, the isolation insulating film, and a portion of the epitaxial layer are removed so as to leave enough of the epitaxial layer to form a semiconductor device.

[Function] In the present invention, an insulating film selectively formed on a first substrate, this insulating film and an epitaxial layer, and a second
A separation insulating film is formed from the thermosetting insulating material between the substrates by heating, and the epitaxial layer is separated on the second substrate by this process.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1(a) to 1(i) are cross-sectional views showing the state of each process step in a method for manufacturing a semiconductor device according to an embodiment of the present invention. First, as shown in FIG. 1(a), p - shaped substrate 41 St02.SiO2 doped with phosphorus on top of gold
．． An insulating film 11 made of either 81 mN4 or A 20 is formed. Next, as shown in FIG. 1(b), the insulating film in the area where the semiconductor element is to be formed is selectively etched to expose the substrate surface. In other words, the insulating film 111 is left in order to separate the semiconductor element. Then, the other insulating film is etched. Next, as shown in FIG. 1(C), n-
A shaped epitaxial layer 32 is formed. At this time, the n-type epitaxial layer 32 is formed only on the exposed surface of the O-type substrate 41 of the insulating film 1111Il, and as a result, the n-type epitaxial layer 32 is
A -type epitaxial layer 32 is selectively formed. Next, as shown in FIG. 1(d), a liquid thermosetting insulating material such as liquid glass (SOG Nispin, ON, Glass) is uniformly applied on the selective epitaxial layer 32 and the insulating film 111. . Further, this thermosetting insulating material may be polyimide. Next, another p-type substrate 42, which will become the final substrate, is stacked on the insulating l1111 and n-type selective epitaxial layer 32 via the liquid glass 12, and their surfaces are bonded together. Next, when these composites are heat-treated, the liquid glass 12 hardens and the insulating film 111 and the liquid glass 12
An isolating insulator 1110 sandwiched between two p'''' type substrates 412 is formed, and the selective epitaxial layer 32 is completely isolated by this film. Next, the D-type substrate 41 side is polished to expose the selective epitaxial layer 32 and the isolation insulating film 10 as shown in FIG. 1<f>. next,
When the n+ type region 20 is formed on a portion of the n- type selective epitaxial layer 32, a semiconductor device in which elements are completely isolated is completed.

For convenience of explanation, only FIG. 1(f) is shown in FIG. 1(a) to FIG.
(+)) and upside down.

Although the above embodiment describes isolation between elements of a bipolar LSI, the present invention can be applied to any other LSI that requires isolation.

Furthermore, in the above embodiment, a p-type substrate was explained, but an n-type substrate was explained.
A shaped substrate may also be used, and in this case, the same effects as in the above embodiment can be obtained.

Further, in the above embodiment, the case where two wafers are stacked is explained, but if the above method is repeatedly applied to a plurality of wafers in a multilayered manner, the present invention can also be applied to LSIs having a three-dimensional structure.

[Effects of the Invention] As described above, according to the present invention, an epitaxial layer is formed on a first substrate using a selectively formed insulating film,
A 21st plate is placed over the insulating film and the epitaxial layer via the thermosetting insulating material, and the composite is heated to form a separation insulating film that separates the epitaxial layer from the insulating film and the thermosetting insulating material, and the semiconductor Since the first substrate 1 isolation insulation layer and part of the epitaxial layer are removed so as to leave as much epitaxial layer as possible in the device, it is easily and effectively applied to semiconductor devices such as bipolar transistors that require isolation between elements. It is possible to create isolation between elements.

[Brief explanation of drawings]

FIGS. 1(a) to 1(f) are cross-sectional views showing the state of each process step in a method for manufacturing a semiconductor device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing the structure of a bipolar transistor manufactured by a conventional method. In the figure, 10 is an isolation insulating film, 11 and 111 are insulating films, 12 is liquid glass (SOG), and 20 is an n+ type region 3.
2 is an n-type selective epitaxial layer, and 41.42 is a p-type substrate. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (3)

[Claims] (1) preparing a first substrate of a first conductivity type; selectively forming an insulating film on the first substrate by exposing a predetermined region of the first substrate; and the exposing a second conductivity type opposite to the first conductivity type.
forming a conductive type epitaxial layer; providing a thermosetting insulating material on the insulating film and the epitaxial layer; and attaching a second substrate of the first conductive type to the insulating film via the thermosetting insulating material. and overlying the epitaxial layer; heating these composites to form an isolation insulating film that separates the epitaxial layer from the insulating film and the thermosetting insulating material; A method of manufacturing a semiconductor device, comprising: removing a portion of the first substrate, the isolation insulating film, and the epitaxial layer so as to leave the epitaxial layer. (2) The method of manufacturing a semiconductor device according to claim 1, wherein the thermosetting insulating material is made of liquid glass or polyimide. (3) The insulating film is SiO_2, phosphorus-doped S
A method for manufacturing a semiconductor device according to claim 1 or 2, which comprises iO_2, Si_3N_4, or Al_2O_3.