JPS5958000A - Manufacture of dislocation-free single crystal semiconductormaterial - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] In the production of optoelectronic silicon semiconductor devices (infrared sensors), indium is generally used as a starting material at a high concentration (silicon doped). Efficiency is greatly related to the indium quality, and in reality it is IO from 1019 per cffl.
An indium atom density reaching 20VC is required.

The value θ"l 10" cm-3 is close to the solubility limit of indium in silicon.

Indium is most suitable as a dopant for the wavelength range of 3 to 5 μm, and since it does not show sufficient sensitivity at longer wavelengths, it is especially suitable for the wavelength range of 7 to 10 μm + aσ).
In 7, gallium is used as a dopant.

It is also known that infrared sensor production 1 requires several thermal aerations. Therefore, in many cases it is advantageous to use a dopant with a small diffusion coefficient.

Thallium and antimony have been found to be suitable substances for this purpose. However, when using not only the combination of indium and gallium, but also thallium or antimony, in order to increase efficiency, it is necessary to Need to dope. That is, thallium θ) on) 10'8 to J per cm3
The density reaches Ol”K, which is the same for antimony <
The density reaches from 1o 10 to 1020 .

Like potassium, indium, antimony, and thallium have extremely high vapor pressures in this case, so it is difficult to incorporate these atoms into silicon with high viscosity. The dopant evaporates quickly and quickly, leaving enough t in the silicon.
vThe only thing you need to keep is C.

West German Patent Application Publication No. 2939492, No. 293
No. 9491, No. 2939460, No. 2939452, No. 2939459, No. 2939451 (1) describes a method of achieving high concentration of dopant (σ) and (θ). A large lattice residual stress inevitably occurs in a semiconductor crystal that has been processed.・A device with an ideal lattice configuration and no impurities is
Although the operating temperature is already related, it is well known that the lowest noise σ) is also θ). Teshiro. Foreign material power; contains i”L
When the temperature rises at the same time, the lattice deforms and the noise increases, and the noise level also rises accordingly.

This invention is based on the recognition that the noise level can be lowered to the lowest possible limit by compensating for the lattice residual stress associated with high doping.

Literature (IBM 'L"ecllnical Discl.
osure Bull-etin, 9 (1967
), p, 1452-1455, between West Germany! It is known from Patent Application Publication No. 22/1709) that a compensating substance should be simultaneously diffused during the diffusion of dopant a in the case of doped semiconductor devices. Above θ
) West German Patent Application Announcement ill :B Diffusion.The Jt denomination chair made in this way (at the tn point, the conventional θ
), but the noise characteristics are still not satisfactory. For example, minimum temperature difference? Although the method of these authors is satisfactory for the fabrication of a sensor for detection, it is not satisfactory. According to the research that formed the basis of this invention, the source of the noise is not in the diffusion region, but within the basic material that generates the surface noise. If it is removed, it will no longer have any important meaning.

Based on this knowledge, the present invention proposes to eliminate the lattice stress in the entire base material without removing the lattice stress in the diffusion region θ). Does the basic doping of the semiconductor store basic material require it? If the lattice stress is maintained and the lattice stress is removed, subsequent heavy doping can be carried out in the diffusion region without any additional measures. The purpose of this invention is to provide dislocation-free single crystal materials in the form of rods and disks to the market and to semiconductor device manufacturers.

In order to make a highly doped dislocation-free single crystal basic material, this method (21) is used to at least partially reduce the internal stress in the crystal lattice caused by the incorporation of the dopant 7 into the starting material. A substance that compensates and has an electrically negative effect σ) At least one substance must be added at the same time, and the substance is the starting material σ) Added to silicon, especially polycrystalline silicon, during its manufacture θ) is easiest. 6 in a way
゜This polycrystalline silicon is made of silicon, especially silicon, by pyrolytic decomposition of a gaseous θ) silicon compound, such as silicochloroform (SiHCl2) or silicon tetrachloride (SiC14), in proportion to the carrier gas, e.g. hydrogen. The JT filter was prepared by depositing it on the surface of the support. During this polysilicon σ) deposition from the gas phase, dopants 71 and compensation substances are added to the deposited silicon. This substance is introduced into the reaction gas in the form of a compound. This compound is introduced as a separate gas stream, but it is also possible to add it to the reaction gas mixture. The amount of incorporated material can be adjusted by selecting the temperature of the compound.

It is also possible to put the semiconductor material together with the doping material and the compensation material into a crucible, melt the material, and then pull the entire material into a dislocation-free crystal rod using the Czycochralski method. In this case, the entire length of the rod is melted. In order to achieve uniform composition throughout the melt, it is reasonable to provide means for compensating for differences in vapor pressure of the 11 tons of material contained in the melt.

Furthermore, it is also possible to diffuse the doping substance together with the compensating substance as basic doping throughout the entire semiconductor material, which is cut into disks, for example.

For example, boron and phosphorus generate a negative lattice stress due to their small atomic radius in silicon, but germanium, tin and lead generate a positive lattice stress.
1- and σ) Negative stress can be canceled out. Alkali metals such as sodium, potassium, rubidium, cesium, etc. and indium can cancel out the lattice forces of silicon doped with phosphorus or boron.

Gata 1 cum, aluminum, antimony, indium,
When thallium is pasted and arsenic is used in a small amount for silicon doping, its large atomic volume causes positive θ) lattice Lvr forces, causing carbon, hydrogen, and oxygen to be
! You can add substances and 1-. Furthermore, fluorine and violet, but also nitrogen and sulfur can be used.

Boron-doped silicon is compensated for by germanium, tin and lead, and phosphorus-doped silicon is compensated for by germanium (thereby compensating for lattice window chipping).

Complement 4' when the doping substance is antimony or indium σ)
In addition to carbon, oxygen, and fluorine, nitrogen and hydrogen are used as the 11 substances2.

Arsenic-doped silicon has a lattice variation coefficient of 10.5σ
), compensation is virtually impossible, but in some cases carbon or oxygen can be added to low concentrations.

What do you mean by doping indium at a high concentration? Do you mean indium fluoride or indium oxide instead of indium?
, it is effective to add it to one body. Due to the combination, indium rhodanide (1ha θ) is also formed, and indium compounds such as In
(Ci'J) and InN are also effective.

A similar effect is expected in the case of thallium θ).
12s, 'r 120 and Tl 20s are recommended as doping agents. When aluminum, gallium or antimony and tin are doped with germanium 1/c, the stop lattice stress O) is compensated by silicon, carbon,
Oxygen and hydrogen should be used.

When germanium is doped with arsenic, phosphorus and boron, tin, lead, lithium, potassium, rubidium, cesium and iodine are used as compensators.

Even if a substance has no effect individually, you can combine several of them to create the basic arithmetic equation of the additive substance!
'l! Since it can be adapted to the atomic radius of the 7J quality, the supplementary award J't1 is a number f + 1! Of course, it is understood that the combination of the four basic qualities of θ) and ′ is also good.

In this invention 1.eta.:, r, when the filtration method is standardized, we start from the idea that all impurity atoms having different atomic dimensions from silicon cause lattice distortion (0). If the impurity atoms are small (ρ), a negative 11′ pentagonal stress will be generated in silicon as the basic material, and if the impurity atoms are large, a positive stress will be generated. The magnitude of crystal lattice stress is determined by the radius ratio of impurity atoms to silicon atoms and the impurity atom concentration σ).
Lattice 1/Agricultural production coefficient Gl (KY defined by the following formula) related to the product.

The magnitude of the lattice stress generated by this Xt is given by the product of the impurity random variation and the lattice zero degree coefficient θ). The atomic density of silicon is 4.99 X I022 atoms/cm', and the atomic density of germanium is 4.41 X I022 atoms/cm'.

The impurity concentration A required to compensate for the lattice stress based on the second σ) impurity Btc can be found by the following equation.

The idea of this invention will be clarified through two examples.

Example 1 Indium with an atomic density of 2.times.10@16 atoms/cm@3 is compensated with carbon.

GKJn= -17,3 Gf (Ko -+14.3 = 2.4' Compensate with a mixture of about 50 parts.

Impurity density K 5b=4 X l O17 atoms/cn+
3G K K 5b=-114 15.4X, +024 The density of oxygen and carbon is 11. zo Jt

Claims (1)

[Claims] 1) When a doping substance is incorporated into a semiconductor material, what is the lattice stress caused by this incorporation? At least f(1
A method for producing a highly doped dislocation-free single crystal semiconductor material, characterized in that a compensating substance which cancels out and becomes electrically ineffective in 5 minutes is added at the same time. 2) Particularly in the production of polycrystalline silicon σ) Compensating substance 7 in the process
The method according to claim 1, characterized in that: 3) Gaseous mixtures of transport gases such as hydrogen I/C J) Silicon compounds such as silicochloroform (SiHCl2
) or silicon tetrachloride (5iC14) by thermal molecule r),
Method 1 of claim 1 or claim 2, characterized in that silicon is produced by depositing silicon on a heated silicon substrate by direct current flow. 4) The method of claim 1, characterized in that the semiconductor material is melted in a crucible together with a doping substance and a compensating substance, and the whole is pulled up by the Czochralski method without producing dislocations. 5) In order to achieve a uniform doping concentration over the entire length of the rod, a device is used to cancel the difference in vapor pressure of the substances contained in the melt. The method described in Section 1 or Section 4. 6) A method according to claim 1, characterized in that the doping substance is diffused together with the compensating substance as basic doping, for example throughout the semiconductor material cut into plate shapes. 7) Method θ) according to any one of claims 1 to 6, characterized in that the silicon doped with indium is compensated with carbon. 8) Antimony? Doped silicon'? : Carbon or oxygen or its σ) Both are characterized by being compensated by vc;
θ) Method described in item 1. 9) Compensation of boron-doped silicon by a combination of germanium, tin, and lead σ) it or its 2tl'-) - a patent claim characterized by "life" θ)Q,
If you are listed in any of the 1st to 6th chapters, please leave. 0) Method according to any one of claims 1 to 6, characterized in that the phosphorus-doped silicon is compensated with germanium. ]】) Silicon doped with borium or phosphorus is supplemented with sodium, potassium, rubidium, cesium, etc. σ) alkali metal 16 and indium oxide. The method described in Izukika from around G. 2) Supplementing silicon doped with gallium, aluminum, antimony, indium or thallium 7 with carbon, hydrogen, oxygen, fluorine, nitrogen and/or sulfur. Patent I characterized by any one of claims 1 to 6 71. Method described in Crab. 1j] Claim 1 characterized in that germanium doped with aluminum, gallium, antimony or tin is compensated by one or several of silicon, carbon, oxygen and hydrogen θ) σ) method described in any one of Items 6 to 6. 14) Claim No. 1, characterized in that germanium doped with arsenic, phosphorus or boron is compensated by one or more of silicon, lead, lithium, potassium, rubidium, cesium and iodine.
6. The method according to any one of paragraphs 6 to 6.