JPS63177513A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To form a junction which has a favorable crystalline property and a depth of around 1.0-2.0mum but can not be formed by merely conducting individual implantation of respective ions by using implantation of specified numbers of phosphorus and arsenic ions in combination through a thin oxide film formed on the surface of a semiconductor substrate. CONSTITUTION:An N<+> type buried layer 2 is formed at a P-type semiconductor substrate 1 and an N-type semiconductor region 3 running as a collector is formed through an epitaxial growth. Then a P-type base region 5 is formed at the N-type semiconductor region 3 running as the collector of a bipolar transistor, for example. The oxide film 7 is prepared and a part of its oxide film where an emitter region 6 and a collector-contact region 4 are to be formed is removed and a thin oxide film is provided. Then phosphorus is ion-implanted by a dose of 3X10<15>-1.5X10<16>/cm<2> and arsenic is ion-implanted by the dose of 3X10<15>/cm<2> or less through the thin oxide film and the emitter region 6 and the collector-contact region 4 are formed. Subsequently, they are treated by heat and the emitter region having a favorable crystalline property and a depth of around 1.0-2.0mum is formed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for manufacturing a semiconductor device in which a highly concentrated semiconductor region is formed by ion-implanting impurities into a silicon substrate, and in particular, ion-implantation of phosphorus ions and arsenic ions. 1.0 to 2.0 μm by using ion implantation
The present invention relates to a method for manufacturing a semiconductor device that forms a junction having a depth of .

[Conventional technology]

Conventionally, high concentration of N was achieved by ion implantation of impurities.
The manufacturing method for forming the type semiconductor region includes:

Phosphorus ions or arsenic ions were ion-implanted singly, and high-temperature annealing at 1000° C. or higher was performed to activate and push impurities.

[Problem that the invention seeks to solve]

The conventional manufacturing method described above has the following drawbacks.

(1) When ion implanting phosphorus ions to form a highly concentrated N-type semiconductor region, in order to remove crystal defects caused by phosphorus ion implantation, it is necessary to implant phosphorus ions through a thin oxide film and then heat the phosphorus ions at 700 to 1000°C. It is necessary to perform annealing at a temperature of 1060° C. or higher, and heat treatment at a temperature of 1060° C. or higher.

In this case, heat treatment at 1060°C or higher is essential to recover crystal defects, and because of this heat treatment at 1060°C or higher, the depth of the bond that can be formed is 2.0 μm or more.
A junction of 0 μm or less cannot be formed.

(2) When arsenic ion implantation is performed to form a highly concentrated N-type semiconductor region, crystal defects caused by arsenic ion implantation can be removed to a level that does not affect device characteristics by annealing at a temperature of 1000°C or higher. recover to. However, a typical integrated circuit having a P-type semiconductor region using boron on the same semiconductor substrate has drawbacks such as the fact that the depth of the junction that can be formed is 1.0 μm or less due to heat treatment limitations.

The purpose of the present invention is to eliminate the drawbacks of conventional semiconductor device manufacturing methods, to achieve good crystallinity, and to achieve excellent crystallinity. , it is an object of the present invention to provide a method for manufacturing a semiconductor device that can form a junction with a depth of 0 to 2.0 μm.

[Means for solving problems]

The method for manufacturing a semiconductor device of the present invention is a method for manufacturing a semiconductor device in which a highly concentrated semiconductor region is formed by ion-implanting impurities. .5 × 1015 × 7cm2 of ion implantation process of phosphorus ions, and 3 × 1
Phosphorus glass is formed by implanting arsenic ions of 0"K/C112 or less and phosphorus diffusion at a low temperature and low concentration of 700 to 900°C, and then at a temperature of 900 to 1000°C in a pure nitrogen atmosphere. A process of heat treatment, a process of heat treatment at a temperature of 950°C or higher in a gas atmosphere containing a trace amount of oxygen in pure nitrogen to push in arsenic impurities and Linnean impurities, and a process of heat treatment at a temperature of 800 to 950°C in a steam atmosphere. The method includes a step of performing oxidation.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a first
FIG. 2 is a cross-sectional view of a bipolar transistor according to an embodiment of the present invention.

First, an N+ type buried layer 2 is formed in a P type semiconductor substrate 1, then an N type semiconductor region 3 which is a collector is formed epitaxially, and then a P type layer is formed in the N type semiconductor region 3 which is a collector of a bipolar transistor. A base region 5 is formed, an oxide film 7 is provided, the oxide film in the portion where the emitter region 6 and the collector contact region 4 are to be formed is removed, a thin oxide film is provided, and a 3×10 ”
Phosphorus ions are implanted at a dose of ~1.5Xl016/c112, and then arsenic ions are implanted at a dose of 3x10/c11 or less to form the emitter region 6 and collector contact region 4. , 700-800
A phosphorus glass layer 8, which is a passivation film, is formed by performing phosphorus diffusion at a low temperature of .degree. Note that this heat treatment is performed at a temperature lower than the heat treatment temperature of the next step. after that,
After stabilizing the phosphorus glass layer by heat treatment in pure nitrogen atmosphere at a temperature of 900-1000℃, 950℃
At the above temperature, impurities are forced into pure nitrogen (in a gas atmosphere containing a trace amount of oxygen of 15 to 1.5%).
Oxidation is then carried out in a steam atmosphere at a temperature of 800°C to 950°C.

With the above manufacturing method, crystallinity of 1.0 to 2.0 is obtained.
It is possible to form emitter regions with a depth of μm.

In other words, in ion implantation of only phosphorus ions, heat treatment at a temperature of 1060°C or higher is required to form an emitter region and recover crystal defects caused by ion implantation, but this heat treatment pushes the phosphorus pure ions into the base. The depth of the junction between the region 5 and the emitter region 6 is 2.0 μm or more, but by using arsenic ion implantation together with phosphorus ion implantation as in the present invention, compared to the case of only phosphorus ion implantation, , it becomes possible to recover the crystallinity at a lower temperature, and a junction between the emitter region 6 and the base region 5 of about 1.0 to 2.0 μm can be obtained.

Note that the process of performing low-concentration phosphorus diffusion at a low temperature of 700 to 800 degrees Celsius involves simultaneously performing low-temperature annealing after ion implantation and forming a dense phosphorus glass layer that acts as a passivation film. The process of heat treatment in a pure nitrogen atmosphere at a temperature of ℃ is the 2nd step.
The high-temperature annealing step in the EP annealing method and the heat treatment step to stabilize the phosphor glass layer are performed simultaneously.

In addition, in order to improve the recovery of crystal defects, the gas atmosphere in the impurity intrusion process is made of pure nitrogen with a concentration of 0.5%.
A gas atmosphere containing a trace amount of oxygen of ~1.5% is suitable.

FIG. 2 is a sectional view of a Zener diode of a second embodiment formed by the manufacturing method of the present invention.

First, as in the first embodiment, an N+ type buried layer 2. is formed on a P type semiconductor substrate 1. Form an N-type semiconductor region 3, then form a high-concentration P-type semiconductor region 9 of a Zener diode, provide an oxide film 7, and remove the oxide film in a portion where a high-concentration N-type semiconductor region 6 is to be formed. After that, similar to the first embodiment, phosphorus ion implantation and elementary ion implantation are used to form an N-type semiconductor region 6.
form. Note that 10 is an Af electrode.

This embodiment is effective when a shallow junction is required to control the Zener voltage.

〔Effect of the invention〕

As explained above, the present invention uses ion implantation of phosphorus ions and arsenic ions in combination to achieve good crystallinity of 1.0 to 1.0, which cannot be formed by implanting phosphorus ions or arsenic ions alone. This has the effect of making it possible to form a junction with a depth of 2.0 μm.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a bipolar transistor formed according to a first embodiment of the invention, and FIG. 2 is a sectional view of a Zener diode formed according to a second embodiment of the invention. 1...P type semiconductor substrate, 2...N+ type buried layer, 3
... N type semiconductor region, 4... Collector contact region, 5... Base region, 6... Emitter region (high concentration N type semiconductor region), 7... Oxide film, 8... Phosphorus glass layer, 9... High concentration P-type semiconductor region, 10...
・A/electrode.

Claims (1)

[Claims] In a method of manufacturing a semiconductor device in which a highly concentrated semiconductor region is formed by ion-implanting impurities, 3×10^1^5
A process of ion-implanting phosphorus ions of ~1.5×10^1^6■/cm^2, a process of ion-implanting arsenic ions of 3×10^1^5■/cm^2, and a process of 700 to 90
Phosphorus glass is formed by diffusing phosphorus at a low temperature and low concentration at 0°C, and then at 900-1000°C in a pure nitrogen atmosphere.
a heat treatment process at a temperature of 800 to 950℃ in a steam atmosphere, a heat treatment process at a temperature of 950℃ or higher to drive in arsenic impurities and phosphorus impurities in a gas atmosphere containing pure nitrogen and a trace amount of oxygen. 1. A method for manufacturing a semiconductor device, comprising a step of performing oxidation at a high temperature.