JPS61114571A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To make a bi-polar SOI construction of simple and stable crystallinity by forming an oxide film in a substrate as a buried insulation layer deeply implanting an oxygen ion. CONSTITUTION:An oxygen ion is implanted in a P-type Si substrate 11, then an arsenic ion is implanted in the substrate 11 which is heat-treated for two hours at 1150 deg.C, a silicon dioxide layer 12 to be made the insulation layer in an oxygen implantation region is formed for a buried insulation layer and simultaneously, a buried layer 13 is formed in an arsenic implantation region activating an arsenic atom. Then, an n<->-type epitaxial layer 14 is grown and an element separation region, a base, an emitter region, etc. are formed in the layer 14.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing bipolar integrated circuits in which a layer of buried conductors is provided in a semiconductor substrate. Applying oxide film formation technology to the manufacturing process of bipolar ICs, a buried insulating layer is formed under the buried layer,
Bibo 2-element S OI (5illeon 0nI
ns++Iator)! [Prior art] To provide a method for easily obtaining an II structure with stable crystallinity. [Prior art] Reducing the capacitance between a substrate and an element or between a wiring and a substrate and increasing the resistance to α-ray soft errors in a semiconductor integrated circuit. SOI that does not have a part that comes into direct contact with the St substrate to measure
8OS (Sllico
The structure of n On 5apphire is attracting attention. As a means to realize the SOI structure, polycrystalline silicon t! ! - SIMOX (Separation), which forms an insulating layer by laser annealing technology for single crystallization, ion implantation of Nl atoms into the substrate, and heat treatment5.
n by Implanted Ox)'gen) technology, which is being actively studied. This SIMOX technology (
In recent years, prototype bipolar devices have been reported that exhibit better characteristics than SOI devices formed by laser annealing. IE Electron Device Letters, pp. 9L-93, Volume 5, March 7, 1984 "Particle-pn Bipolar Transistor 7 Applications on Verit Oxide S OI J
(IEEEELECTRON DEVrCE LETT
ER8%p, 91-93, VOL, EDL-5, NO,
3, MARCH1984: VertlcmI n-p
-n Blpolar Transistors F
ascribed on Buried 0xi
[Problems to be Solved by the Invention] SO8 has drawbacks such as increased current leakage and decreased charge mobility due to lattice mismatch between the 27F substrate and the silicon epitaxial layer, and high cost of the sapphire substrate. In the case of the annealing technology, it is not possible to obtain a stable single-crystal SOI, and no examples have been reported showing good characteristics in bipolar devices.
MOX technology (in the above prototype example, there is no buried layer, so
The drawback is that the series resistance of the collector cannot be lowered.

In the present invention, the sor! The object of the present invention is to realize a bipolar element that can easily obtain a stable crystalline state even though it is a sorm structure by utilizing the lithium structure, and can also reduce the series resistance of the collector.

[Means for solving problems]

In the present invention, impurity atoms that provide a conductivity type and atoms that can combine with substrate constituent atoms to form an insulator are ion-implanted into a semiconductor substrate, and heat treatment is performed to form a low-resistance conductive layer and at the same time to form a buried insulating layer. It is done by forming.

〔Example〕

Embodiments will be described below with reference to substrate sectional views shown in FIGS. 1 to 4.

In FIG. 1, 400% of oxygen (0) is applied to a P-type Si substrate 11.
Ion implantation is performed at K e V, lxl 0 "cx-" or higher, and then arsenic (As) is implanted at 60 to 70 Ke\, IX
Ion implantation is performed at a depth of 10"cm-".

At this time, the scattered atoms are distributed at a depth of 0.5 to 1.0 μm, and the arsenic atoms are distributed at a depth of about 0.5 μm from the surface. Instead of arsenic, the implanted ions may be N-type impurities such as phosphorus (P) or antimony (Sb). The order of injection can be arbitrary;
The acceleration voltage and ion implantation amount are controlled for each substance.

In the vKz diagram, 2
Silicon dioxide = r y which becomes an insulating layer in the oxygen implanted region by the oxygen ions implanted in the previous process after being subjected to heat treatment for several hours.
(S 101) layer (or 5iOxN) 12 is formed as a buried insulating layer, and at the same time, arsenic atoms are activated in the arsenic implanted region to reduce the crystal defect density generated by ion implantation to at least 1lla! Layer 1 recovers to below /- and becomes a buried layer
form 3.

In FIG. 3, an n 2 epitaxial layer 14 is grown on the substrate.

In FIG. 4, a U-shaped trench reaching the buried oxide film layer is formed in the region of the epitaxial layer 14 for device isolation by anisotropic dry etching, and then the diagnostic trench is filled with an oxide film and polysilicon to form the device. Complete the isolation area.

Thereafter, a collector reach-through region, a paste, an emitter region, etc. are formed according to a normal bipolar element forming process.

〔Effect of the invention〕

As explained above, according to the present invention, S with excellent crystallinity
Since the OI structure can be applied to bipolar devices with a buried collector layer, it is possible to reduce the capacitance between the substrate and wiring or between the base W and the device while keeping the collector resistance low, and to improve the resistance to α-ray soft errors. It becomes possible to manufacture large bipolar integrated circuits.

[Brief explanation of the drawing]

1 to 4 represent cross-sectional views of the substrate at each step in the embodiment of the present invention. 11...P-type silicon substrate, 12...buried insulating layer, 13...buried layer, 14...
-Epitaxial layer, 15...Silicon dioxide film. Figure 1 number ÷ ◆ φ ↓ ( ↓ ↓ ↓ ↓ Building 2 Figure 3 Figure 4 Figure procedure amendment (method) % formula % 1932 patent application No. λ3G et al. )'l- Relationship with (I Fraudulent applicant's address
Kanayo Prefecture 11 teams? City 1t; flx: I knee 1-11
10151fr land (522) Name Fujitsu Limited

Claims (1)

[Claims] Forming a low-resistance conductive layer and a buried insulating layer at the same time by ion-implanting impurity atoms that give a conductivity type and atoms that can combine with substrate constituent atoms to form an insulator into a semiconductor substrate and performing heat treatment. A method for manufacturing a semiconductor device, characterized by: