DE2545628A1 - ON-BOARD SEMI-CONDUCTORS - Google Patents

Description

you. ing. H. TiXiGEXIiANK <-ιοτ; υ · mrx, .- iG. > ί. ΙϊΛϋΟ.Γ. · Ru-i ..- r «Υο. V /. ^ CIlMITZ PJ ^ Ia-C] B. GEAA3.FS - mvl.-ikg. W. WEIlXiSIiT x> ifi ..- i> i: ys. V /. CAIiSTJiNH

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Π ·: ΐ.Κΐ ·· ΟΛ · (OtsiJ) 5. '{. ·} O5 8H TO 1 OdO, Ob.iO A3666 / USA Ι _ΗΜ Κ. SBOiDi. '* VEST M

, October 10, 1975

Boron doping of semiconductors

The invention relates to semiconductors with diffused Transition and especially in a new way, silicon and germanium semiconductors doping with boron, more precisely the invention relates to a precise and easily controllable method, a boron-containing layer in at least one part of the Diffuse into the surface of a silicon or germanium semiconductor, to create a semiconductor junction in it,

Semiconductors have been known in the industry for many years, and the term semiconductor element is used for silicon, germanium and silicon-germanium-legioxide. Vie him here is used, the term "semiconductor" is intended to mean silicon, germanium, and silicon-gernianium-legiorto HalbIu-itorelements describe. 609827/0828

.-TSClIZ 3iM To SItISTRO (BtK ViIiTOOOO) M «. 03/23107 · I .-. LllSOSB »DA ^ iC to. ! IAMIItTIIi. (BI 2 30 (180000) Kn.!>; Ti IIiKtr. · ΗιΜΗΓΙΙ »« Il Mil.

Such elements can be circular, rectangular or triangular odoi 'of every · andoron geometric form, although they are in are disc-shaped in most commercial situations.

Such silicon semiconductors have an active impurity, which oinge during manufacture or spatula 'by diffusion- « is brought, this pollution affects the electrical Equivalent chemistry line of semiconductor in contrast to others Impurities that have no noticeable influence on this characteristic to have. Active contaminants are commonly referred to as donor contaminants or acceptor contaminants. The donor impurities consist of phosphorus, arsenic and Antimony, and the acceptor impurities of boron, gallium, A3-urainium and indium. In other cases the silicon.m ~ Semiconductors essentially free of such impurities and are called intrinsic semiconductors.

With reference to the nomenclature as used in semiconductor technology, a region of the semi-conductor material which has an excess of donor impurities and thus an excess of fx electrons is said to be n-conductive. On the other hand, p-conduction is generated by a region that has an excess of acceptor impurities, from which a deficit of electrons or an excess of holes results. In other words, η-conduction is characterized by electron conduction, whereas p-conduction is characterized by hole conduction. Self-silicon half-shafts ¹ (sometimes called "I" -type) contain neither donor nor acceptor

6.09827 / 0828 _ _

expeditions.

If an η region is adjacent to a p region in a continuous solid piece of semiconductor material, the boundary between these two is referred to as pn or np excess and the piece of semiconductor material is referred to as pn junction IIalbloiter. If a p-type area is next to an area with an even larger p-type, the junction is called a p ~ f> junction. If there is an n-conductive area next to a Boreich with an even larger η-line, the transition is called an n-n ' transition. There are also pI and nI type semiconductor junctions. The present invention involves diffusion doping with boron to form a ρ (including ρ) region in the above types of semiconductors.

Semiconductors are used and used as rectifiers, Transistors, photodiodes, solar batteries, semiconductor controlled to Rectifiers and other devices. In addition to the usual electronic application, the p ~ n junction of a semiconductor often used as a radiation detector or a charged particle detector.

"Various developments took place in previous manufacture instead of achieving the doping of semiconductor material by adding the doping impurities while the silicon crystal was pulled from the melt, or by using alloy. ·? - and diffusion methods in the growing crystal. Usually the diffusion of the doping

609S27 / 0S2S - 4 ~

substance achieved in the silicon material that a certain amount of the respective doping material together with the silicon is heated wix'd so that the doping atoms penetrate the semiconductor body from all sides. An acquaintance Method refers to the phosphorus doping of silicon.

Methods of depositing the dopant material to a limited extent Areas of the surface of the semiconductor body are described in U.S. Patent No. 3,287,187. This earlier manufacturing method requires the deposition of an oxide on the semiconductor material by vapor deposition, this is followed by the Diffusion of the dopant into the semiconductor surface by heating the semiconductor body.

Semiconductors containing a diffused pn junction have been made by heating an n-type silicon semiconductor in the presence of a decomposable gaseous boron compound, as disclosed in US Pat became. It is believed that the boron forms a vitreous film on the surface of the semiconductor and gradually, with continued heating, some kind of boron diffuses into the silicon. The previous state of the art also provides for a boron compound to be deposited on the surface of the silicon semiconductor at low temperatures, followed by heating to a temperature at which diffusion takes place. Other techniques for diffusion deposition of boron include the deposition of gaseous BpO "from molten boron oxide as in US Patents 3,041,214, 2,19,8h6 and 3h93,355 .

609827/0828

Recently, the use of oxidized boron nitride plates as a source of boron in doping silicon semiconductors was discussed in the article "Boron Nitride as a Diffusion Source for Silicon" by N. Goldsmith et al. proposed published in the RCA Review June 19 ^ 7 on page ^ hh . The dissertation "The Use of Hot-Pressed ° -3 / £ ig ^Gn Boron Nitride Plates as Boron Diffusion Source for Silicon Solid-State Diffusion", submitted by David B. Rupprecht to the Department of Electrical Engineering of the Graduate School of the University of Pennsylvania in June 1972, concerns a related technique . Equally of interest is the article "Oxidized Boron Nitride Plates as an In-Place Boron Doping Source for Diffusion in Silicon" by D. Rupprecht and J. Stack, published in the September 1973 issue of the Journal of Electrochem, Soc, Solid State Science and Technology . In this boron nitride technology, the boron nitride is oxidized by an oxidizing atmosphere before it is used as a diffusion source. This creates a 3 "0" layer on the boron nitride surface, which later decomposes and supplies the boron for the diffusion process. The process is limited by the fact that the thickness of the B "0 layer increases the amount of boron available for diffusion and, if there is insufficient amount, the limit of solubility of the solid has not been reached and control of the uniformity of the diffusion process is very difficult. Accordingly, in performing the prior art process, closed control of boron nitride oxidation is very problematic.

609827 / 0S28 - 6 -

All of these earlier techniques have complex operational features that drive up the costs of semiconductor production.

A first aspect of the present invention includes a method of uniformly distributing boron into a silicon semiconductor surface to diffuse in.

Another object of the invention relates to a new solid source or supplier of the boron which is used for diffusion is used in the semiconductor surface.

Yet another object of the invention relates to providing a method which uses a _{glass ceramic body containing B 2} ^ as a doping material source for the controlled application of B "O" vapors to the surface of a silicon semiconductor element.

Yet another object of the invention is to provide a solid source capable of releasing BpO_ vapors and can be used repeatedly for the controlled and uniform doping of a semiconductor surface. ,

Another item is a second embodiment and; improved Version of the invention that uses a special family of B "0" containing glass ceramic donor material dispensers, which are thermally stable and solid at doping temperatures of over are approx. 1050 C. The preferred range of compositions

609827 / 0S28

for doping material dispensers made of glass ceramic is solid at temperatures in the region of 1100 * to 1200 C, even in the form of thin disks. Furthermore, the original glass compositions that were thermally crystallized to form these improved glass-ceramic dopant dispensers are easy to melt and resistant to uncontrolled fossilization, allowing B _? 0 "in the order of 60 mol- '/ o in the doping material dispenser made of glass ceramic, the strength and spatial stability being maintained during the doping at high temperatures. This feature is extremely important because the amount of generation of the B "0" vapors by the glass ceramic dopant dispenser during doping usually increases as the concentration, for example of the BpO ", in the dopant dispenser increases. Unfortunately, the thermal stability and strength of the glass-ceramic material in thin parts decreases with increasing B ₂ O_ concentration. In this way, a unique and desired combination of a high concentration of B "0" in the doping material dispenser made of glass ceramic with thermal stability and strength at temperatures of over 1050 C is achieved, even if the doping material dispenser is in the form of thin disks. ,

A problem with the use of a high concentration of Bp ^ T ^ - ^s * f is that if doping is not used at high temperatures (e.g. above 1050 ° C) the boron is doped in such a high amount that a much stronger precipitate occurs the semiconductor arises when it can be dissolved and diffused into the semiconductor.

609827/0828

When the semiconductor being doped is made of silicon, the reaction of the excess boron with the silicon forms a precipitate of undesirable composition which is believed to be borosilicide. This undesirable compound is visible as a dark brown or bluish-yellow dye, depending on the thickness. It is assumed that the color and intensity of this dye is dependent on the amount of undesired precipitate because of the interference pattern. The bluish yellow dye indicates a greater accumulation of undesirable precipitate. This precipitate is by nature electrically insulating and must be removed from the doped semiconductor. The box silicide compound is not easily removed by washing with hydrogen fluoride and is usually "lost" for disposal by an oxidizing reaction in an oxygen-containing atmosphere. The precipitation of this borosilicide compound is usually more pronounced when fresh boron dopant dispensers are used.

Another object is a third embodiment and further improved version of the invention that is unique and desired concentration combination of BaO, B "0, AlpO “and SiOp in the doping material dispenser made of glass ceramic used to provide a controlled doping rate at high temperatures (e.g. - ^, 1050 C), which reduces the tendency to form of undesirable insulating precipitate as well as thermal stability and strength at temperatures above 1050 C even if the dopant dispenser is in the form of

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thin slices is reduced.

The above and other embodiments, improvements, and advantages of the invention will be apparent from the following detailed description; clearly in connection with the drawings, whereby:

1 shows the sectional drawing of a semiconductor body, which was prepared according to the process described herein.

Fig. 2 is the true-to-length view of a solid doping material dispenser made of glass ceramic _{containing B o} 0_, as it was described here,

Fig. 3 is an elevational view showing a fire resistant container shows, in which a number of solid wafers of the glass ceramic containing B 0 ″ and a number of silicon wafers are arranged to use the present invention.

The invention overcomes the previous difficulties in that it forms a solid, dimensionally stable glass ceramic body made of alkaline earth compounds which is free from alkali oxides. The first embodiment includes a glass-ceramic body that is at least about 10 mol- $ B _? 0 as a source or donor of doping material for transporting the B ₂ 0 "in gaseous state to the semiconductor. A second design and improved version contains a doping material dispenser made of alkali-oxide-free alkaline earth aluminum borosilicate glass ceramic as the doping material source "

60 9 8 27/0828 - 10 -

or dispensers for the transport of B '0 “in the gaseous state to the semiconductor. Xn is the improvement of the third embodiment an alkali metal oxide._fröier barium aluminum borosilicate glass kerarailc » Used dopant dispenser.

According to the invention, the doping material dispenser containing B 0 “becomes made of glass ceramic in vaporous connection (in an or Absence of a carrier gas) with a semiconductor held at a temperature for a time sufficient to B_0_ from the doping material donor onto the surface of the To transport semiconductors. The semiconductor treated in this way is then heated, with or without the further presence of the glass-ceramic Doping material for a period of time that is sufficient to allow the boron to diffuse into the semiconductor into the to enable the desired depth.

A commercially significant embodiment of the invention is a n-type silicon semiconductor in which a boron-containing Layer was formed which forms a p-type region. the Backside of the silicon chip or wafer retains its n-conductivity, and accordingly is that by this invention Item produced a semiconductor with a p-n junction.

The invention has been described by the term "transport of the BpO in the gaseous state ", as a clear Vex-admission the boron-containing species that evaporates from the glass-ceramic dispenser is absent. Accordingly, this term includes any for the A boron-containing species responsible for the transport effect,

609827/0828 - n -

Likewise, the diffusion process is described by the Term "Bordiffusion" in the semiconductor, as a clear understanding of the boron-containing species that actually go into it! diffused, absent.

Accordingly, this term includes any for the diffusion doping effect responsible boron-containing species.

The boron differs from the gaseous one. Phase to the surface of the semiconductor and diffuses into the silicon wafer to a controlled depth. Dio concentration and depth of the transition is proportional to the time and temperature of the Doping and diffusion process.

The composition of the B "0" Dotiermaterialspenders containing glass-ceramic is critical in that it sufficiently B "0 must contain, on a B O _{0 0} enriched vapor) phase at

usual doping temperatures in the range of about 700 ° C. to about 1200 ° C. It has been found that the Dotiermaterialspender of glass ceramic at least about 10 mole-96 must contain at B ₂ ⁰ T, "0 deliver vapor zti, wherein a lower molar percentage of B ₂ 0 'to B requires sufficient high temperatures. The glass ceramic doping material must be solid and dimensionally stable at the doping temperatures so that no deformation problems occur when the doping material source is in a flat position. In the case of planar diffusion doping, there is a planar surface of a solid doping material donor and a planar surface of the semiconductor that is being doped

609827/0828
ORIGINAL INSPECTED

should, parallel to each other during the diffusion drive treatment. Since the concentration of B 0 "on the obex surface of the semiconductor is a function of the distance between the planar surfaces, the räumliclie stability of Dotxermaterxalspenders of utmost * importance in order to achieve uniformity in the boron distribution on the surface of the silicon semiconductor .

The glass-ceramic dopant dispenser particularly useful in the use of the present invention is formed from certain magnesium aluminum borosilicate glasses that are substantially free of alkali oxides. With essentially alkali-free it is meant that the glasses _{contain only enough alkali oxides (eg K ^ O, Na?} 0 and Li_o) in order not to supply a vapor phase which contains such oxides at the doping temperatures. It has been found that the presence of such alkali oxides in the vapor phase induces undesirable properties in the electrical conductivity of the resulting semiconductors. In the usual use of the present invention, the proportion of alkali oxides is less than about 0.5 mol-56 and preferably less than 0.1 mol- ^ o of the glass-ceramic doping material mixture. Preferably no alkali oxides are contained at all, although this is not always possible as the standard material often contains alkali oxides as impurities * ^;

The term "glass-ceramic" body is used here in accordance with its usual Meaning used and refers to a semi-crystalline Ceramic body, which consists of at least one crystalline phase, the

609827/0828

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randomly dispersed in a leftover glass-like phase is composed. Such crystalline phase is created by thermal crystallization in place of an original one Glass mix formed.

The heat treatment process for forming glass-ceramic from an original glass usually includes nucleation substantially at a cooling temperature (viscosity 10 poises) of the original glass, a state of formation at a temperature below the phase softening point of the original glass (preferably at a viscosity in the region of 10 to 10 poises) and a state of crystallization (at a temperature preferably between 150 ° to 300 ° F (6 $ to 150 ° C) above the filament softening point of the original glass (ie, viscosity of 10 'poisan).

Although the crystallization process itself is not the subject of the present invention, the following description is made in the Interest in the completeness of the disclosure given. The original glass that is to be crystallized will be on

1 3 heated to a temperature corresponding to a viscosity of 10 poises and held at that temperature long enough to allow the formation of submicroscopic crystals dispersed in a vitreous material. This is commonly known as nucleation. The time required for nucleation period depends on the composition and is typischerwoise between i / 4 ^ d? H hours. 603 8 27/0828

The vitreous material that contains the nuclei, is then heated to a temperature having a viscosity of

corresponds to about 10 poison. This thermal condition is maintained for a long enough time to allow partial crystallization to form a solid crystalline structure. The submicron nuclei dispersed in the vitreous material as the result of the nucleation phase provide growth centers for the solid framework that forms during this second or developmental phase in the heating cycle. This Ent "" development phase depends on the composition and typically is l / 4 to h hours. The purpose of this phase of development is to create a solid skeleton crystal-like bracing, to support the remaining material when the temperature is raised to complete crystallization "

This glass-ceramic body is then formed by heating luxig to a temperature of 150 to 300 ° F (65 to 150 ° C) above the temperature corresponding to a viscosity of 10 poison of the original glass. This temperature is maintained until the desired degree of crystallization is reached. The final crystallization phase in the heat treatment cycle is typically 1 / k to h hours, and in some embodiments of the invention it is the highest possible temperature that the glass-ceramic has not yet liquefied. This hit treatment promotes spatial stability at high temperatures in the finished glass ceramic. This heat treatment temperature is in the neighborhood

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the solidification temperature,

In practical application it has been found that all three stages of the heating process can be achieved, by moving the temperature continuously through the ranges of Nucleation, development and crystallization is increased. In many compositions of the present Invention was found to be a "formal" stage of development is not necessary because the time it takes for the product to move from the nucleation temperature to the To heat the crystallization temperature is sufficient. Further details on the production of glass ceramic bodies are given in TJS Patent 3,117,881, the disclosure of which is attached here as a reference.

In application of the first embodiment of the invention, the doping material dispenser made of glass ceramic is made from magnesium aluminum borosilicate glass, such as a (MgO.A1 "O"). B ₂ O ".5iO ₂ glass, which is essentially free from alkali metal oxides and mainly from the following components in mole percent.

Wide area Preferred area

component Mol% SiO ₂ 2-50 Al ₂ O ₃ 15-36 ^B 2 ° 3 10-50 MgO 15-36

5-30 20-30 25-50 20-36

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Usually the total amount of alkali metal oxides is !! less than about 0.5 Mo 1- $ "and preferably less than 0.1 Hol- % in the above compositions.

The term "consisting essentially of" means that in addition to the above oxides, minor amounts (i.e., up to about 10 mol- ^) of other than alkali oxides are included are, such as glass-forming oxides, modifying oxides, nucleating oxides (e.g. TiO and / or ZrOp) and Separation aids when such additives are needed special chemical or physical properties reach.

An essential feature is that the doping material dispenser made of aluminum borosilicate glass ceramic contains at least 10 mol of B _p 0, which can be present in the vitreous phase, in the crystalline phase or in a mixture of both. The following Examples 1 through 17 illustrate the first embodiment of this invention.

In applying a second embodiment of the invention, the one Improving the first, the dopant dispenser is made of glass-ceramic from an original glass Formed alkaline earth aluminum borosilicate, which is essentially free from alkali metal oxides and mainly from the consists of the following parts in MoI- ^:

- 17 -

609827/0828

where k

Component SiO ₂

.O _n

, B ₂ O ₃ RO

RO

where RO is: MgO CaO SrO BaO

1.5

wide area. Mol-tf 15-40 15-30 20-60 5-25

0-15 0-10 0-10 0-10

Nb ₂ O ₅ Ta ₂ O ₅

0-5
0-5
0-5

Usually the total amount of alkali metal oxides is less than about 0.5 mole-ji, and preferably less than 0.1 mol $ in the compositions given above.

In a preferred application of this second embodiment of the invention, the compositions are within the above specified range essentially consists of:

- 18 -

Preferred area component

SiO ₂ 18-40

Al ₂ O ₃ 15-30

-B ₂ O ₃ 3O-6O

RO 5-15

where h 3- Al ₀ O ₀ 3- 2
RO

the MgO content of RO being less than 3/4 of the total composition amounts to.

As follows from Examples 18 to 57, the combination of MgO with CaO, SrO and / or BaO improves the resistance to uncontrolled fossilization of the original glass. The presence of La ₀ O. ,, Nb ₀ O and Ta ₀ O contributes to melt and to form the original glass compositions (ie more than about 50 mol $) a high proportion have B _o 0_ which resists the uncontrolled Versteinung , at.

In addition to the above oxides, the expression "consisting primarily of" indicates that small proportions (ie up to about 10 mol ~ $) of other than alkali oxides are also involved, such as glass-forming oxides, modifying oxides, nucleating oxides (e.g. TiO ₂ and / or ZrO ₂ ) and cleaning aids, if such ingredients are not harmful to the semiconductor doping and are necessary to achieve specific chemical or physical properties.

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The relation fr- ^ is important from the point of view; of the glass shape

RO

The ability to change and the high temperature stability of the resulting Doping material dispenser made of glass ceramic. ΐ / οηη the Vei - Al O

ratio ■ is less than about 1.5, the RO

glass ceramic doping material donor discs have a tendency to Deformation at the doping temperatures in the vicinity of 1100 C

Al ₂ O up to 1200 C. If the ratio of ~ "7Τ ^ Γ is greater than about h , the melting and deformation of the original glass becomes more difficult.

In applying the third embodiment of the invention, illustrating a second enhanced version is the Dofciermaterialspender from Glaslceramik formed of a VLT sprünglichen glass Bariumaluminiumborsilikat which is free from alkali metal oxides essentially and mainly consists of the following components in mol $:

further area component Mo l.- ° k

kO <£ -60 ₃ 10-30

BaO 1-15

Petroleum oxides from 3-20 that from BaO, MgO, CaO, SrO or their Mixtures existing group selected

where h ^. Al "0_

Alkaline earth oxides

- 20 -

60 9 8 2 7 / OS 2 8.

Usually the total amount of alkali metal oxides is less than about 0.5 mole and preferably less than 0.1 yiol-fo in the above compositions.

In an application of this third embodiment of the invention, both because of the long service life and because of the more efficient and controlled boron doping and spatial stability at high temperatures is preferred, the composition consists within the above range 'mainly from:

preferred area

component > 2 Mon 1 - % SiO ₂ ho < -55 Al ₂ O ₃ 10-30 B ₂ O ₃ 20-40 BaO 3-15 Alkaline earth oxides 5-15 where k> ■ ^A1 2 ° 3

Alkaline earth oxides

As can be seen from Examples 58 to 63, the increased Combination of BaO with MgO and other alkaline earth oxides eliminates the area of glass formation and enables a long service life, spatial stability and a controlled boron doping

rate at high temperatures,

In addition to the above oxides, the term "means mainly consisting of "the inclusion of minor proportions (i.e. up to about 10 MoJ .- #) of other than alkali oxides such as

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For example glass-forming oxides, modifying oxides, kerabelling oxides (e.g. TiO and / or ZrO ") and cleaning aids, if such components are not harmful to the semiconductor doping and are necessary to obtain special chemical or physical properties.

The ratio 2 3 is important in relation to the

Alkaline earth oxides

Glass formability and high temperature stability of the resulting Doping material dispenser made of glass ceramic. When the relationship

of 2__2 is less than about 1.5 »own the

Alkaline earth oxides

glass ceramic doping material disks have a tendency to deform at the doping temperatures in the vicinity of 1100 C to

1200 ° C. If the ratio of 2 ^ .. is greater than some

Alkaline earth metal oxides is ferry h is the melting and deformation of the original

Glass more difficult.

In accordance with the present invention and with reference to the accompanying Drawings, a suitable η-conductive silicon substrate 10 'using one of the known techniques to produce a To obtain monocrystalline silicon body, prepared. For example, a monocrystalline ingot can be made of high purity Silicon are formed. The ingot is cut into transverse pieces and the cubes are cut to form the To deliver silicon wafers of the desired dimensions. The surface of the substrate can be cleaned and cleaned properly Polishing to be prepared. However, the polished and cleaned semiconductor silicon material can be obtained commercially. The polishing or cleaning of the surface can be done by mechanical

609-327 / 0828. ₂₂ _

~ 22 -

Means like sanding or the like or by chemical means like etching, what in the previous one can be completed The art is well known and does not form part of the present invention.

Furthermore, the η-conductive silicon wafer can be part of a complex semiconductors and already have one or more p-n junctions in any geometric arrangement. The only important feature is that at least one part the present surface of the silicon wafer has η-line. Accordingly, the term η-conductive silicon as used herein also includes complex semiconductors that alternate Have p- and η-conductive zones.

In the case of conventionally grown crystals, the surface can be chemically polished with a suitable etchant, e.g. a solution of three parts by volume of hydrogen fluoride, three One volume part acetic acid and five volume part nitric acid. On the other hand, the surface can be sanded or etched with a hot solution of water containing about 10 $ sodium hydroxide at room temperature or up to about 90 ° C will. These cleaning and etching work serve the. Distance· of pollutants from the surface and deliver a uniform Surface of particular smoothness, this preparation work are already well known.

It was found that the formation of a p-n junction according to the present invention to the extent desired

6 Q-9 8 27 / Qg2 £ - 23 -

an η-conductive silicon with a specific ¥ idez'stand of about 10 ohm centimeters arises. It is of course easy to see the exact size and nature of the disc is not critical. For example, the commonly used disks can be 1.2 or 3 inches (2.5, 5, or 7.5 cm) in diameter or own more. The thickness can range from 5 to 20 mils (0.125 bob and 0.5 mm), although this can also be changed. Typical discs are between 8 and 10 mils (0.2mm and 0.25mm) thick. Likewise, the specific resistance is suitable η-conductive silicon starting materials between 0.0001 and about 100 Ohmxentimeter.

As shown in FIG. 1, an oxide layer 11 is grown on the surface of the disc 10 in accordance with this invention. The disc is _{heated in the B p} O "vapors so that a film or layer is deposited over at least a portion of the surface * - flat of the disc forms. A mask or protective layer can be used to create any pattern as is known in the art. The layer or film 11 is vitreous in nature and contains boron in some form. The temperature of this process is designed so that at the same time some boron diffuses from the film or precipitate 11 into the disk 10 and there forms a thin surface layer or area 12 containing boron adjacent to the coating 11. The region 12 represents a barrier or boundary which is formed in the section between the surface layer 11 penetrated by the boron and the η-conductive silicon 10. The depth of the transition zone can vary, but is

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- 2k -

usually up to about 10 micrometers thick. The minimum diclce can vary and is about 0.1 micrometer,

In, on or under this vitreous layer 11 is the electrically insulating deposit, which consists of borosilicides is formed. The third embodiment of the invention reduces the tendency for this insulating deposit to form and facilitates the removal of these minor amounts can form.

Fig. 2 shows a plate or disk of the B ₂ O ″ containing doping material holder made of glass ceramic, which serves as a supplier for the B_O ″ vapors for contact with the silicon disk *

When it is placed in a suitable furnace of the type used for the invention and exposed to the appropriate temperatures, the glass-ceramic doping material disk releases BpO "vapors, which then pass through the high temperature zone of the furnace to contact the silicon wafers that are in are attached in the vicinity of the doping material disks, flow. In the application of the first embodiment of the invention is derTemperatui "range 700 ° C to 1200 ° C and more particularly 85O ⁰ C to 1100 ° C. In the second and third embodiments, the temperature is between 700 ° C and 1,250 C, and more specifically should be between ^O 1050 ° C. and 1200 ° C. Overall, the method for diffusing boron into a semiconductor silicon element consists in introducing at least one semiconductor silicon element into a furnace, as well as placing a solid doping material disc, plate or similar body in the furnace in the neighborhood,

609827/0328 '

- 25 -

but not introduced in direct contact with the silicon element, then the silicon element and the glass-ceramic-like doping material are subjected to an elevated temperature in the range described above. In these Tempei'aturen the dopant is B free _o 0 "vapors, which then flow through the furnace and contact dos Siliziurnelementes in contact with at least part of the surface. This process is sustained for a sufficiently long period of time to allow diffusion of the bora into at least a portion of the surface of the silicon element to form a diffusion zone therein. After the B _? O "vapors react with the hot silicon surface, and with continuous heating the elementary boron diffuses into the silicon chip. This boron diffusion step can, if desired, be carried out in the absence of the glass-ceramic doping material disk.

In a further embodiment of this embodiment of the invention, the doping process is further controlled and improved by a free flowing inert carrier gas such as argon or nitrogen is used. As used here, the term means "Inert gas" means that the carrier gas does not enter into any chemical reaction with the B "O ^ vapors and the hot silicon surface.

This is shown in Fig. 3, in which the carrier gas enters from the left and flows over the disk ~ \ h where the B _? 0 is released and touches the available surfaces of this silicon wafer 10. By storing two silicon wafers back to back, the back of each of the silicon chips comes off

60 9 827 / 0-82 8 " ²⁶ "

not in contact with the boron and accordingly retains theirs original property as η-conducting silicon »when carried out of the doping process, the Diffusionstio.fe can continue can be enlarged by a simple heat treatment in an inert atmosphere the transition diffuses deeper down, If desired, this can be done in an extra oven. This process has been described as applied to silicon semiconductors because of its great commercial importance. The same Process can be used for germanium semiconductors, although slightly lower temperatures for the doping of germanium must be used because of its melting point of 937 C,

When preparing the glass-ceramic doping material, suitable starting materials that have the appropriate compositions must be melted to form a homogeneous glass mass. For example, compositions described above at 15OO C to 165O C in a heat-resistant crucible be melted to form a homogeneous glass. Usually this melting process takes from about 15 minutes up to several hours to achieve homogeneity. It can be desirable be able to add additional BpQ_ to the melt to reduce the Compensate for losses through evaporation. It is desirable to keep the melting time as short as possible in order to keep the losses due to evaporation low. Also should be the source material be as pure as possible to minimize the presence of impurities. The doping material donor can be made in several ways. The original glass can be made from organometallic derivatives

609827/0828

- 27 -

melted in order to remove the contents of undesired

in

share as low as possible, such as the jointly transmitted U.S. Patent 3,660,093 to the contents thereof Reference is made here, or it can be made from the usual high purity glass-forming components are melted.

It is desirable that the glass or glass-ceramic be free from impurities that have high vapor pressures at 900.degree. C. to 1200.degree. Obviously, the presence of impurities can adversely affect the electrical properties of the doped silicon semiconductor. Impurities that must be particularly avoided or kept to an absolute minimum are alkali oxides (i.e. Li ₂ O, Na ^ O, K _? 0, Cs ₂ O or Rb_O) and other metal oxides with high vapor pressure, such as PbO, CuO and SnO ₂ .

After the glass compositions have melted and form a homogeneous molten mass, the glasses can be put into each desired shape can be brought. Usually this takes place by placing the glass in preheated graphite molds, which are in the shape of a right circular cylinder with a diameter approximately that of the final diffusion discs is equivalent to. The glass can then be exposed to the cooling process, and after cooling the glass bars become oäer Cylinders removed and checked for cracks and then sliced, usually between 0.025 inches and thick 0.1 inch (0.625 mm and 2.5 mm). Own at this point the panes of glass take shape in order to convert them into glass ceramic.

6Q9827 / GS28 - 28 -

Another possibility is to subject the glass ingot or a part drilled out of the core to a heat treatment to form the glass ceramic, this glass ceramic is then cut into slices; the very close control made possible by the present invention can contain a larger amount of silicon elements by a suitable arrangement of a larger amount of glass ceramic doping material disks in a container, as in Pig. 3 shown.

In the implementation of the invention, the doping is carried out, by arranging the glass ceramic doping material chips close to and parallel to the silicon wafers that are to be doped without touching them. In general, the distance in which the best results are obtained is determined to be about 1/8 of an inch (3 mm). In a slotted quartz glass container or another fire-resistant crucible, vessel or similar can 100 or more silicon chips or wafers of the same thickness are doped by alternating a glass ceramic wafer and a pair of slices back to back with juxtaposed Front sides are arranged, wherein the silicon wafers and the glass ceramic wafers are essentially parallel are to each other. The usual arrangement can according to FIG. 3 happen.

The time and temperature of the doping conditions are selected so that that you have the appropriate p-n junction depth and sheet resistance for the desired task. This is shown in the following examples.

- 29 -

The spacing of the chips in the container and the selection of the surrounding inert carrier gas and flow rate are due the requirement that the silicon chip in show the direction of the flow of the surrounding gas contain the same amount of doping as those pointing against the flow.

The various embodiments of the invention are further explained in the following examples in which all percentages Mol- $ and all temperatures are given in C, unless otherwise indicated. Examples 1 to 17 relate to the first embodiment, examples 18 to 57 to an improved second embodiment and Examples 58-63 a third and further improved version.

example 1

Part A

Preparation of the glass-ceramic doping material ami! IGnsntziin ^ A stirred reaction vessel is filled with 1132 g of ethyl silicate, 750 ml of ethanol, 60 ml of water and 6 ml of 1 η nitric acid. The mixture is stirred briefly and left to stand for several hours until the ethyl silicate is hydrolyzed *

A solution of 4 ^ 95 S of secondary aluminum butoxide in 500 ml of secondary butanol is slowly added while stirring the hydrolyzed ethyl silicate. The reaction is slightly exothermic and the amount added is such that the temperature of the reaction mixture remains below 50.degree.

- 30 -

S 09 8 2-7 / 03

When the addition of the secondary alumina oxide is complete, 100 ml barrels are added with constant stirring, then 2609 g trimethyl borate. The mixture obtained is pretty gel-like and diluted by adding 4000 ml of water. After dilution, 3 ^ 8 g of magnesium oxide in Added in small portions with constant stirring to obtain an even dispersion of the magnesium oxide. the The reaction mixture is then stirred for a further 20 minutes.

The reaction mixture is poured into shallow plastic dishes which are placed in a forced air oven kept at 60 ° C to allow the solvent to evaporate. After evaporation of the volatile solvents, a fine white powder is obtained. The powder is dried at 150 C for about 20 to 2 hours. Approximately 25OO g of dry powder are obtained.

The Pulvex * is placed in a platinum crucible and at about

C melted for 5 hours with occasional manual stirring to form a clear, homogeneous glass having a molar composition of 15 $ SiO, 34.7 $ B 0 ~, 25.2 $ MgO, and 25.2 $ Al ₂ O ₃ possesses.

Part B

Formation of the doping material as dispenser from glass ceramics The molten glass of part A is poured into a preheated graphite mold, which has the shape of a straight circular cylinder. The dimensions of the cylinder are 2 l / h inches (5 »7 cm) in diameter and 3 inches (7.5 cm) in length. The one containing the glass

6 09 8 27 / Q-8 2S-

- 31 -

The mold is heated to 671 ° C.

Heating takes about 1 / h to 1/2 hour. Then the molds are cooled and the glass cylinder removed. The cylinders are cut into "slices between 15 and ^ O mils (Ο, 'ί and 1 mm) thick,

The disks are carefully stacked in a heat treatment oven and the temperature is brought to 8 * 4-5 ° C. in order to initiate thermal crystallization on the spot. The panes are kept at this temperature for h hours, then the temperature is increased to 867 ° C. and the panes are kept at this temperature for a further hour. Finally, the temperature in the heat treatment furnace is increased to 1100 ° C. The disks are held at this last temperature for an additional hour, after which the oven is switched off and allowed to cool to room temperature overnight. The non-porous glass ceramic panes obtained in this way are removed and dried in order to use them in the B 0 diffusion doping.

Part C.

Level diffusion doping · ■

The planar diffusion doping is carried out by some of the glass ceramic discs according to Part B of about i / 4 inch {0 _t 6 mm) of the silicon wafers, to be doped are removed, and parallel placed opposite to them. The glass ceramic disks and silicon disks are arranged in slotted quartz glass bowls, with a glass ceramic plate alternating

60 98 27/0828 - - \ z -

disk, two silicon disks back to back, a glass ceramic disc, etc. are arranged. The arrangement is roughly in Fig. 3 shown.

The silicon wafers used in this example originally have η conduction and have a specific one Resistance of approximately 9 ohm-cm.

The assembly is placed in a diffusion furnace and argon gas is passed through as an inert carrier gas, as in FIG. 3
shown at a rate of 500 cm / minute while maintaining the temperature at approximately 1050 ° C. These conditions are respected for one hour.

At the end of this diffusion doping period, the silicon wafers are cooled to room temperature and purified with dilute hydrogen fluoride.

The surfaces of the doped silicon wafers are p-conductive. Surface measurement of the doped disks with a four-point conductivity probe and the surface resistance were measured to be approximately 13 ohms me ^. It is estimated that the pn junction is about 3 to h micrometers below the surface of the silicon wafer. At the end of the diffusion doping process, the doping material disc had neither collapsed noticeably nor deformed in any other way. When an η-conducting germanium semiconductor is doped according to the present invention,
slightly lower doping temperatures must be observed,

609827 / 082'8 ^; - 33 -

ORIGINAL INSPECTED

since the melting point of germanium is 937 C.

Various diffusion doping attempts were made after the above Procedure carried out by changing the parameters time and Temperature as set out below. In any case, the endowed rejected Silicon wafer p-conductivity.

48 hZ 30th 25th 32 17th 12th \ 6 26th 20th 14th 10 18th 13th 10 - 8th

Flat, contrary to the pd o tierton Sil lgluMSchalbo (Ohui.

Temperature (° C) Time (hours) 1/2 1 2_.

1000 1025 1040 1050

Example 2

Part _- A.

if? of the glass ceramic. Dopierraatorialsponderjs Highly pure inorganic starting materials, which contain technical oxides and carbonates as reagents, are used to deliver 500 g starting material, which consists of 15.7 mol-fo SiO ₂ , -

41.3 mol- $ B "0", 21.5 mol- 56 Al 0 and 21.5 mol- # MgO. The starting material is filled into a platinum crucible, and the crucible is placed in an oven and heated to 15JfO ⁰ C. The crucible is heated for approximately 6 hours with occasional stirring to form a molten, clear, homogeneous glass. The glass is removed from the furnace and solidifies in a cooling furnace that is kept at one temperature for about 1/2 hour

609827/0 £ 2ß -3 ^ -

- 3k -

held by 650C wix'd.

Part B

The crucible is removed from the cooling furnace, cooled, and cores are drilled off from ο'αιη solidified glass. 2 l / k inches (5i7 cm) in diameter and 3 inches (7 »5 ^cn 0) in length. The kernels are then cut into slices which

the dimensions are as described in Example 1 "bssitzcn, le-Ji- ^ li
/ Temperature and time 852 ⁰ C for 1 Stxmdo and dio ICnd

The time and duration is I 100 Ό for 1 hour, before the 0.Coti is switched off and the room has cooled down.

Part C.

Eb ene Di FFUs ions d o t ier ung

The planar diffusion doping is done with the panes from part B as in Example 1, with the exception that the temperature is 950 C and the argon flow rate and temperature can be set as described below. The measured values indicate that the resistance decreases with increasing doping time. The change in resistance is due to the increasing p-botation traced back.

- 35 BOSS 27 / -QS 2 8

184 90 39 23 93 75 69 4ο 53 40 32 28 71 44 35 33

Fläc henwi resistor d he do p- animal th Slliziuinnc hoiborr (Ohmj

Argon flow rate (cm / min.) Time (hours)

1./2 1 2

The reason for the measured value 184 0 \ uaJt // P at a time of 1/2 hour and an argon flow rate of 100 cm / min. is not clear, although it is assumed that the conductivity is just changing from η to ρ.

Another experiment is carried out as above with the change, that the argon flow rate is 550 cm / min. and the spacing is 1/8 inch (0.3 mm) instead of 1/4 inch (θ, 6 mm). In the doped silicon samples is p-doped, and the values in are plotted below as a function of time.

Time (hours) 0hm / cm 1/2 57 1 St. 2 37 4th 31 Examples 3 till 9

Glass ceramic dopant dispensers are made from glasses of the composition, as indicated in the following table I, produced »

., $ •• 09 82 7/0828 " ³⁶ "

.-.- * ORIGINAL INSPECTED

The process of melting and crystallizing the glasses is described in Part A of Example 2, with the modification that the temperatures have the values given in Table I,

The crystallized glass ceramics are taken out of the crucible and parts of them are prepared for the plane diffusion doping.

The diffusion doping is carried out by the doping material donor A η-conductive silicon wafer with a specific resistance is placed on the bottom of a silica dish of about 5 ohm-cm, the Silicon bowl mounted in a vertical position and approximately 1/2 inch (1.25 cm) from the dopant dispenser.

The silica shell structure is placed in a diffusion oven, through the argon at a flow rate of 500 cm / min. flows like is shown in Fig. 3, while the temperature at 1000 C is held. These conditions are observed for 1 hour with each round.

At the end of the diffusion doping time, the silicon disk opens Cooled to room temperature and observed visually. Interference noise, which indicate the presence of a thin film are displayed on all silicon wafers., which are indicated in the following table are observed. The surface of the silicon wafer is then cleaned with diluted hydrogen fluoride.

The surface conductivity of the silicon washer is tested, all silicon wafers have p-conductivity.

6,99827 / 0828 _3? _

TABSLLE I

Oxide Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9

SiO ₂ 3.9 9 _t 6 3.5 9.0 3.4 8.8 14.2 B ₂ O ₃ 47.1 44.6 39.3 37.0 32.2 30.4 28.6 CJ
O
CD
CO
to MgO
^A1 2 ° 3 24.5
24.5 22.9
22.9. 28.6
28.6 27.0
27.0 32.2
32.2 30.4
30.4 28.6
28.6 7/0823 Raw material
shatters
temperature (C)
Crystallization 1533
311 1594 1538 1594 1538 1538

Hit ζ ebehandlung

4 hours 69O ⁰ C S21 ° C 700 ° C 710 ° C 720 ° C 837 ⁰ C 840 ° C

+
1 hour 835 ⁰ C 865 ⁰ C 820 ° C 845 ° C 865 ⁰ C 865 ° C 895 ⁰ C

1 hour 1000 ° C 1000 ° C IGOO ⁰ C 1000 ° C 1000 ° C 1000 ° C TCO0 ° C ΪΝ>

- '■ CJl

CD NJ OO

B ice pi oils J 0 ρ is .__ l 7.

The following additional examples further describe the Features of the present invention and provide additional doping data as well as a qualitative indication dex · thermal Stability of the glass ceramic dopant dispenser. Glass ceramic Dopant dispensers are made of glasses, which make up the composition given in the following table II, horgestöJ.lb, The glass quality is also given in the table, the compositions which provide clear, archaic glasses were found to be good other compositions than opal. The procedures kxim Melting and crystallization of the glasses are in parts A and Part B of Example 2 described, with dex * modification, da / 3 the Temperatures have values as indicated in Table II below.

self
A "flex test" developed is shown in the table below. In this test, glass rods about 1/8 inch (3 mm) square and about 1/8 inch (2.8 cm) in length are made from the specified glass and formed into a glass-ceramic body using the specified crystallizations! treatment crystallizes. After crystallization, each glass ceramic rod is placed on a surface on either side so that the final dimensions are 1 1/8 inch. i / 8 inch, ΐ / ΐό inch (2.8 cm. 0.3 cm. 0.15 cm). Each glass ceramic rod is then placed over a platinum crucible 7/8 inch (2.2 cm) wide (with 1/8 inch (3 mm) excess length of the rod on the dome crucible) and placed for 1/2 hour in a temperature range between 1000 and held at 1250 ° C. The amount that the 1/16 inch (0.15 cm) thick rod "bends" or its flatness

60 9 82 7/0828

- 39 .-

deviates, gives an arbitrary indication of the resistance to thermal deformation. Since the size dex · thermal Deformation or deflection that can be tolerated, depending on the thickness of the sample, the doping time and the doping temperature varies according to the situation, a deflection of more than approximately 0.3 mn * in the above procedure corresponds approximately to that maximum allowable deformation for a very thin (e.g. about 20 mil (0.5n »m) thick) doping disk of about 1 to 1 1/2 inches (2.5 to 3 »75 cm) diameter in a dotior array like her is shown in FIG. Thicker glass Korani doping material ~ molds can be used at higher temperatures.

The planar diffusion doping is as in Part C of Example 1

that
dui ^ led, with the modification / the diffusion doping time is 1/2 hour at the temperatures given in the table. Results of this doping are entered in the table.

The data in the table shows a tendency that the deformation assumes with increasing temperature, although a good thermal stability for very thin glass-ceramic rods is observed.

- ho -

TABLE II
Example No. 10 11 12 13 I h I5 16 17

840 787 866 630 - -, - 8.03 823 683 653 725 Well 630 649 668 657 Well Well Well opal Well Well OD3..1

Mole fo

^Si o ₂ 36.0 24.0 33.4 25.0 35.0 30.0 30.0 37.6

^B 2 ° 3 ^{e 2h} > ° ■ 36.0 14.8 40.0 35.0 35.0 30.0 30.0

^M §0 20.0 20.0 25.9 17.5 15.0 17.5 20.0 16.2

^A1 ₂ ° 3 20.0 20.0 25.9 17.5 15.0 17.5 20.0 16.2

Glass peculiarities

Thread softening point ⁰ C

Cooling temperature C
Glass quality

Crystallization heat treatment

C for 16 hours 86O 700 76Ο 700 700 700 700 700 ° σ for 1 hour 1100 1000 II50 1100 1θ4θ 1θ4θ 1100 1100

Bending test

Deviation in mm
at ⁰ C for 1/2

Hour

1000 0 0.3 0, 0 0.2 0.2 0.2 0.5

1100 0> 3 0 73 -3 7 3 > 3 y> 3

1200 0.2> 3> 3

Sheet resistance
after p-doping
at ° C for 1/2
Hour '

1000 55 28 - 31 375 28 28 27

1100 - - hl - ■ - - ;

1200 2

- kl -

09 8 27/0828 »

Ex iel 18

Part A

Usual high purity raw materials are in a platinum crucible at 154o ° C for 5 or 6 hours with manual stirring melted to obtain a clear, molten, homogeneous glass of the following composition.

Mo _- I ^ Weight- ^ SiO ₂ 15.7 12; 8 B ₂ O ₃ 41.3 39.3 Al ₂ O ₃ 28.7 4o, o MgO 14.3 8.0

The molten glass is removed from the furnace and at room temperature cooled down. The glass, still in the crucible, is placed in a cooling furnace kept at 65O C, The Glass is heated to 65O C for 1/2 hour and then removed And cooled to room temperature.

part B

Crystallization heat treatment

The crucible with the clear glass contents is placed in a heat treatment furnace brought and the temperature increased to 09O ° G. The crucible was exposed to the temperature of 69O C for 3 hours. The temperature is then increased to 805 ° C. and the crucible is exposed to this temperature for 1 hour. Then the temperature increased to 1100 C and the crucible exposed to this temperature for 1 hour. Then the stove is switched off and

609827/0828 -42-

- hz -

temperature before the crucible is removed. The non-porous glass-ceramic material obtained in this way has a milky white appearance. A 1 1/2 inch (3 »75 cm) core is sawn out of the glass ceramic material with a hole saw and cut into thin slices with a diamond saw, the thickness between 15 and kO mils (θ, ' ! mm and I mm),

Level D if £ η s i ο η s d ο ti ο: nin g, ·

The planar diffusion doping is durchgο: leads by einigo 1/8 to 1 cent inch (0.3 to 0.6 mrn) of Part B Glaskerarnikscheiben approximately dio to be doped from the Siliziumscheibon are arranged and these are opposed to parallel, the Glass ceramic panes and silicon panes are arranged in slotted quartz glass bowls with alternating positions of a glass ceramic pane, etc. The usual arrangement is shown in FIG.

The silicon wafers used in this example are originally η-conductive and have a specific Resistance of about 9 ohm-cm,

The assembly is placed in a diffusion furnace and argon and a flow rate of 500 cm / min. passed through as an inert carrier gas, as shown in Fig. 3, while the doping time and Temperature is set as shown below.

When this diffusion doping period ends, the

609827/082 8 " ^kJ "

Silicon wafers cooled to room temperature and diluted with Hydrogen fluoride cleaned.

The surface of the doped silicon wafers has p-conductivity. Surface tests of the doped clay discs with a four-point conductivity probe. The surface resistance in ohms Mff # of the doped silicon samples thus obtained are given below as a function of temperature. That doped silicon is p-conductive.

Distance i / 8 to Λ / h inch (0.3 to 0.7 "in) - Flußrato: 500 cm ^ / min argon.

it 2 Time 1 (Hours) 4th , 5 temperature 71 , 0 64.7 2 5h ,8th 95O ° C 5h , 5 42.7 56.0 26th , 5 100O ⁰ C 16 14, O 38.5 6th 1078 ⁰ C 10.0

The doping material disks are at the end of the diffusion doping process not visibly collapsed or otherwise deformed. When an η-conducting germanium semiconductor is to be doped according to this embodiment of the invention, are slightly lower temperatures due to the germanium melting

point at 937 C.

A few more diffusion doping tests according to the method given above were carried out, with the parameters time and temperature

- hh -

609827/0828

ORiQlMAL INSPECTED

48 42 30th 25th 32 17th 12th 16 26th 20th 14th 10 18th 13th 10 8th

.. 44 -

temperature would be changed as indicated below, in any case -wui'den the doped silicon wafer has p-conductivity.

Surface resistance of p-doped silicone clips Temperature * (° C) Time (hours)

Example 1? up to 4-7

Glass ceramic doping donor disks are made from glasses Composition, as indicated in the following tables Uluiid XV, manufactured. The process of melting and crystallization of the glasses are as described in Example 18, only the temperatures are kept at ¥ ert as indicated in Tables III and IV, and the molten glass becomes quenched by placing it as a plate in a flat metal bowl at room temperature "instead of as in Part A of Example 18 to cool down. Table III describes mixtures in which MgO is the only "RO" component and Table IV describes various compositions of "RO" components.

The results of a "Bend ^{Test 11} are set forth in the Tables below. In this test, glass rods approximately ^{1/8" (0.3 mm} ) square and about 1 1/8 "(2.8 cm) long are made from the indicated glass and to a glass ceramic body with

609827/0828 -45-

Crystallizes with the aid of the specified crystallization heat treatment. After the crystallization, every glass ceramic rod was included both sides on one level so that the final dimensions are 1 i / 8 inch. 1/8 inch. i / i6 inch (2.8 cm. 0.3 cm, 0.15 cm). Each glass ceramic rod is then placed over a platinum crucible 7/8 inch (2.2 cm) wide (length

überrcigfc
1/8 inch (θ, 3 mm) / the rod the crucible) and

exposed to a temperature range between 1000 and 1250 C for 1/2 hour. The amount by which the 1/16 inch thick rod "bends" or deviates from the planar shape is an arbitrary indication of the resistance to thermal deformation. Since the tolerable size of the thermal deformation or deflection is different depending on the sample thickness, doping time and doping temperature, a deflection of more than approximately corresponds. 0.3 mni in the above implementation is about the maximum allowed defoliation for a very thin (about 20 mil (0.5 » ^11T 0) wafer of about 1 to 1 1/2 inches (2.5 to 3» 75 cm) diameter in a doping arrangement as shown in Figure 3. Thicker glass ceramic doping material shapes can be used for higher temperatures.

The values given in the following tables show that the tendency to deformation increases with increasing temperatures, although good thermal stability for very thin glass-ceramic rods at temperatures above 1050 C and even at

\ O

higher temperatures of 1250 C is observed.

609827/032 «

25A5628

TABEL ; III 700 21 22nd 23 24 Example no. 19th 20th 1260 24.0 30.0 30.0 37.5 Mole * 15.7 36.0 26.7 - 26.7 23.3 21.7 Al ₂ O ₃ 28.7 26.7 36.0 30.0 35.0 30.0 B ₂ O ₃ 41.3 24.0 0 13.3 13.3 11.7 10.8 MgO 14.3 13.3 0 2 2 2 2 Al ₂ O ₃ AMgO 2 2 0 clear clear clear opal Glass texture some clear
Crystals 0.2 Crystallization
heat treatment 700 700 700 700 ° C for 16 hours 700 1200 1200 1200 1260 ° C for 1 hour 126O Bending test 2 Deviation in ram
at ° C for i / 2
hour 0 0 0 0 1000 0 0 0 0 0 1100 0 0 0 0 0 1200 0.3 0 0.2 0.2 0.2 1250 0.5 Sheet resistance
(μ. ^ m) ³ ^ ⁸ - ⁰ * ¹ p-
Doping at ° C
for 1/2 hour 29 30th 19th 32 1000 38 7th 7th 5 7th 1100 8th 2 2 2 2 1200 2

6Q9827 / Q82S ORIGINAL INSPECTED

- 47 -

Example no.

TABLE III (cont. S.) 25 26

MOl-J ₆ 35.0 22nd , 5 30, 0 25, 0 20, 0 23, 0 Al ₂ O ₃ 20.0 21 , 7 20, 0 - 23, 3 26, 7th 25, 7th V ₃ 35.0 45 , 0 40, 0 40, 0 40, 0 38, 5 MgO 10.0 10 , ß 10, 0 11 7th 13, 3 12, 8th Ai ₂ o ₃ / Mgo 2 2 2 2 2 2 Glass texture opal opal opal some a ige some

Crystals KüsfeD-e crystals

Crystallization heat treatment

⁰ C for 16 hours
⁰ C for 1 hour 700
126O 700
I26O 700
1260 700
126O 700
1260 700
1260 Bending test Deviation in mm
at ° C for 1/2 "
hour

1000 1100 1200

Areal resistance (-ft-Jtafc) after p- doping at C for 1/2 hour

0 0 0 0 0 0 0 0 0 0 0 0 0 0.2 0.2 0 0 0 0.2 1.6 0.9 0.5 0 0.7

27 29 28 29 28 26th 5 7th 8th 8th 9 8th 2 2 2 2 2 2

- 48 -

609827/0828-ORIGINAL INSPECTED

TABLE III (cont.)

Example no.

^A1 2 ° 3

B ₂ O ₃

MgO

Al ₉ O, / MgO

Glass texture clear

Bending test

Deviation in now at ⁰ C for 1/2 hour 1000 1100 1200 1250 surface resistance

after _o p-doping at C for 1/2 hour 1000 110O 1200

33 9

25, 0 20.0 23 , 0 20.0 25, 0 21 0 22.5 23 ,1 - 20.0 16, 7th 40, 0 ^ 2.5 38 , 5 50.0 50, 0 ο 15.0 15th 10.0 8th, 3 1, 5 1.5 1 , 5 2 2 kl a r clear clear opal some
Crystals

Crystallization
hi t 'Λ ebjehlungs 700 700 700 700 700 ° C for 16 hours 1260. I26O 1200 1260 I26O ο ⁺
C for 1 hour

0 0 0 0.2 0 0 0 0 0.5 0.6 2.8 > 3 2.6

- k ₉ -

827/082 8
ORiGIMAL INSPECTED

Example no.

TABEL IV 0 - • J8 .39 4o 4i 36 V 7th 25.0 15.7 15.7 15.7 25.0 25, 0 16.7 28.7 28.7 28.7 16.7 16, 8th 50.0 '4i, 3 41.3 41.3 50.0 50, 3 8.8 9.3 9.3 11.3 8.8 8th, 3.3 9.3 9.3 11.3 3.3 3, 5.0

^B 2 ° 3

MgO
CaO
SrO
BaO

La ₂ O ₃

Ta ₂ O ₅
Glass texture opal

Crystallization

heat treatment

⁰ C for 16 hours 700

⁰ C for 1 hour 1260

Deviation in mm at ° C for 1/2 hour 1000
1100
1200 0.9

1250 4.0

Sheet resistance ") according to p-

clear 5.0 2

clear

Doping bex
for 1/2 hour C. 28 33 27 1000 3 8th 2 1100 2 * 4th 2 1200

609827/08 2 8 ORIGINAL INSPECTED

3.1 5.0

clear

29

3.1

5.0

some clear crystals

700 700 700 700 700 I26O I26O I26O I26O 1260

6th 0, 0 0, 0 0, 0 0 0 0 2, 0 8th 2, 9 2 , 5 0, 2 3 1 ,1 0

47

Example j- ol No.

TABLE IV (cont.) 42 4j

Mole-96
SiO "

Al ₂ O ₃

MgO CaO SrO BaO Al ₂ O ₃ / HO La a ° 3 Nb 2 ° 5 Ta 2 ° 5

20.0 20.0 25.0 22.5 15.7 20.0 16.7 13.3 21.7 24.7 50.0 55.0 55.0 - 45.0 47.3 10.0 8.3 6.7 8.8 12.3 5.0 3.3 8.8 7.3

5.0

5.0

2 2.0

Glass texture some clear

Crystals

Crystallization heat treatment ^

G for 16 hours 700 C for 1 hour 126θ

700 1260

Bending test

Deviation in mm at ⁰ C for 1/2 hour

clear

700 I26O

1000 0 0 1100 0.1 o; o 1200 1.0 0.8 1250 4.3 5.0 Sheet resistance
(Λ- ^ Βτ) after p-
Doping at ° C
for 1/2 hour 1000 32 33 1100 9 1200 609 8 2 7/0328 ORIGINAL INSPECTED

2.5
2.0

clear

700
I26O

30th
11

5.0

22.5 21.7

45.0

10.8

5.8

5.0

some clear KrdstaLlß

700
I26O

700 1260

0 0 0

0 0 0

3.5 0.7 0.8

4.0 3.5

32

- 51

TABLE IV (cont.) Example No. 48 4_9 50 51 52

SiO ₂ MgO 25.0 25.0 15.7 15.7 10.0 Al ₂ O ₃ CaO 23.3 23.3 24.7 24.7 30.0 ^B 2 ° 3 SrO 40.0 4o, o 47.3 ' 47.3 45.0 RO BaO 9.7 11.7 12.3 7.3 10.0 ai ₂ o ₃ / ro 9.7 6.7 7.3 7.3 10.0 La ₂ O ₃ Nb ₂ O ₅ 5.0 Ta ₂ O ₅ . 5.0 Glass texture 2.4 2 2 3.4 3 Crystallization
hi t ζ ebehandluns 2.0 5.0 ⁰ C for 16 hours ⁰ C for 1 hour 5,, 0 clear clear some
Crystals clear some
Crystals 700 700 700 700 700 1260 • 1260 1260 1260 1260

Bending test

Deviation in mm at ⁰ C for 1/2 hour

1000 0 0 0 0 • 0 1100 0 0 0 0 • 0.5 1200 1.3 0.3 0.3 0.8 4.6 1250 5.0 2.9 4.5 * FlächemdLderstand
(jQ. £ | ^) after p-
Doping at ° C
for 1/2 hour

1000 32 32 35 36

1100 9 8 9 9

609827 / 082-8 " ^ "

ORIGINAL! MSPECTEC

TABEL IV (cont.) 55 56 2545628 Example no. 53 5h 57 Mole fo 15.0 22.5 SiO ₂ 15.0 15.0 21.7 21.7 20.0 Al ₂ -O ₃ 31.7 16.7 52.5 ^ 5.0 20.0 B ₂ O ₃ 37.5 6o, o 9.5 9.5 50.0 RO 10.8 8.3 5.8 5.8 5.0 MgO 10.8 3.3 5.0

CaO SrO BaO

ai ₂ o ₃ / ro

La ₂ D ₃ 5.0

Nb ₂ O Ta ₂ O ₅ glass texture some

Krist.

Crystallization heat treatment

5.0

2.0

3.7

5.0

some opal crystals

1000 1100 1200 1250

Sheet resistance

0.5 3.0

0 0

1.3> 3

0 0

0.6 > 3

φ according to p-doping at ° C for 1/2 hour 1000 1100 1200

28

36 10

6 0 9 8 2 7 /._(^S_2 3 ' ORIGINAL INSPECTED

3.7

5.0

5.0

some some Krist. Krist,

⁰ C for 16 hours 700 700 • 700 700 ' 700 ⁰ C for 1 hour 1260 1260 1260 I26O 1260 Bending test Deviation in mm at ⁰ C for 1/2 hour

0 0

0.6

^ 3

31 9

3h 9

- 53 -

Example 58

Part A
at the.
One / pound (0.453 kg) of high purity starting materials is melted in a platinum crucible at 1620 C for about 5 to 6 hours in an electric furnace in an air atmosphere with occasional manual stirring to obtain a clear, molten homogeno glass mass of the following composition:

component Al ₂ O ₃ Mol% ^B 2 ° 3 29.6 Ai ₂ O ₃ 19.0 Alkaline earth oxides 8.5 BaO 5.4 MgO 3.1 2.23

Alkaline earth oxides

The molten glass is removed from the furnace and poured into a steel form · (at room temperature), a cylindrical cavity of 2.5 inches (6.3 ^CIn) deep and 2.5 inches has (6.3 cm) diameter. When the glass reaches the point where it becomes stiff and strong, it is immediately placed in a heat treatment furnace at a temperature of 720 ° C. and subjected to the following crystallization heat treatment.

part B

Crystallization heat treatment The glass cylinder of Part A is heated for 16 hours on a temperature

609827/0823 - 5h -

temperature of 720 ° C kept. Then the temperature increases to 1200 C increased and held for 1 hour. Then the furnace is switched off and cooled to room temperature. The non-porous one obtained in this way Glass ceramic cylinder has a milky white opal appearance,

The glass ceramic material is uniform to one diameter 1 1/2 inch (3 »8 cm) by means of a grinding wheel and with the help of a diamond saw into several thin Glaskeraniische Discs about 40 to 100 mils thick (1 mm to 2.5 mm cut.

Part C.

Plane diffusion doping

The planar diffusion doping is carried out by arranging the glass ceramic disks of part B about 1/8 to 1 / h inch (0.3 to 0.6 cm) from the silicon screws to be doped and in parallel opposite them. The glass ceramic discs and the silicon discs are set up in slotted quartz glass bowls with a glass ceramic disc etc. arranged alternately. The arrangement is shown in FIG.

The silicon wafers that are used in this example originally have η conduction and have a specific resistance of about 0.1 to 0.5 ohm-cm. '

The assembly is placed in a diffusion furnace by the nitrogen at a flow rate of 1 l / min, as an inert Ti ^ aging gas as shown in Fig. 3 flows during the doping time

098'2 7/08 2S - 55 -

i / 2 hours at a temperature of 1150 C.

At the end of this diffusion doping period, the silicon wafer becomes to room temperature atagelcuh.lt. Then the silicon wafer is using dilute hydrogen fluoride etched to form the vitreous layer to remove. The silicon wafer is checked, and only a barely visible color on the surface shows the presence of some borosilicide.

The surfaces of the doped silicon wafers are p-conductive. The surface tests of the doped disks are carried out with a four-point conductivity probe. The surface resistance is about h OhmJ ^ p. The light color does not prevent the measurement of the surface conductivity.

The doped disks (even the thin disks of hO mil (1 mm) thick) are neither collapsed nor otherwise deformed at the end of the diffusion doping process, so that they would be unsuitable for further planar doping, if an n-type germanium semiconductor according to the present invention is doped, slightly lower temperatures are required because of the germanium melting point at 937 C »

The previous steps are repeated with; the modification that during the last 5 to 10 minutes of the doping period Oxygen gas is used instead of nitrogen gas at the same flow rate. Under these conditions there is still one slight color visible on the silicon after doping,

- 56 - --fiJD-9 8 2 7 / Q 8 2 8

ORIGINAL INSPECTED

but it is completely removable by using the hydrogen fluoride etch. The surface resistance of the doped silicon obtained is approximately h

Example 59 Part A

The following table shows the extended operating time of the Dopant dispenser according to the present invention, itself after extended periods of time under demanding operating conditions in terms of. Time and temperature. As used herein, the term "Betx ^ iebszeit" refers to the whole Period of time in which the specific dopant dispenser was used for actual doping. In many applications the usable life of the dopant dispenser was not exceeded even after 800 hours of operation.

In Table A below is the temperature for the previous one Operating time the same as the temperature for the listed doping test. The doping materials and processes are like those in Example 58 with time and temperatures as given below.

- 57 -

6Ö9827 / G828 _

ORlQiMAL INSPECTED

TABLE A

Operating time temperature flow resistance (hours (before ο after p-doping this test) -

Time (hours)

1/4 1/2 1

233 171 115 86 107 78 56 43 52 39 32 24 31. 21 lo 12th 14th 10 7th 7th 5 4th 3 4th 3 3 2

45 875

64 925

820 975

735 1025

64 1075

64 1125

172 1150

132 1175

59 '1200

At the end of the tests described in 'Table A above, the Doping disks not collapsed odex * otherwise deformed, so that they would be useless for further planar doping. The physical appearance of the doping disks is essentially the same as before the doping, and they still have the same doping ability at the end of the test, although the doping disks have not been treated or refreshed in any way.

Furthermore, the silicon wafers that have been doped with the doping material and an operating value of more than subjected to about 150 to 200 hours, no dark color on what little or no borosiliacid compounds on the surface indicates. In the examples where a light color

- 58 609827 / QS28

ORIGINAL INSPECTED

it can occur through the addition of oxygen in the Doping furnace towards the end of the doping period, followed by a Hydrogen fluoride etch.

part B

In order to further demonstrate the features of this third embodiment of the invention, doping methods and materials were used as in Part A of this example (with the exception that the silicon to be doped was originally η-conductive with a specific ¥ ider _t of k to 7 ohms. cm is used. The time is 1/2 hour, the individual doping material dispensers having experienced a previous operating time as specified at the same temperature as the test temperature described. The doping was carried out at two test temperatures of 975 ° C and 1025 ° C. The results are given in Table B below.

previous

Operating time

TABLE B.

Sheet resistance (g ^ after p-doping at 975 for 1/2 hour

Surface resistance after p-doping at 1025 ^° C. for 1/2 hour

39 37 36 36

39 37

40

21 18 21 21 21 '

20 22

22nd

609827/0828 ORIGINAL INSPECTED.

- 59 -

TABLE B (cont.)

previous surface resistance operating time after p-doping at 975 ° C for 1/2 hour

375 400 425 450 475 500 525

39

39

39

¹ H.

ko

37 39

Surface forest stand (f after p-doping at 1025 ° C for 1/2 hour

21 21 21

22nd

22nd

23

23 21

At the end of these test periods, none of the dopant disks (even the thin 40 mil (1 mm) thick disks) were deformed and retained their flat shape which made them suitable for additional

60 -

^ 0.9827 / 0828 ORIGINAL INSPECTED

- 6ο -

makes level doping processes. The physical appearance of the
Doping disks were essentially the same as before doping and the doping capacity was still present at the end of the test, although the doping disks were not treated or refreshed in any way.

Furthermore, the silicon disks, which would be doped with the doping material, have an operating time of more than
150 hours of use did not appear dark in color, indicating the presence of little or no borosilicide compound on the surface.

Examples 60 to 63

To further illustrate the features of the third embodiment of the invention, various dopant dispensers have been selected
Barium aluminum silicate glass ceramic produced and according to the
Methods of Example 58 evaluated. The results are given in Table V below.

- 61 -

6-09827 / 0828

TABEL V 61 62 2545628 60 Example no. 55.0 55.0 63 Mole-56 46.8 11.0 17, -0 SiO ₂ 20.6 30.0 20.0 48.0 Al ₂ O ₃ 25.4 4.0 8.0 13.0 B ₂ O ₃ 7.3 3.0 5.0 35.0 Alkaline earth oxides 5.5 1.0 3.0 4.0 BaO 1.7 2.75 2.13 3.0 MgO 2.85 1.0 ■ Al 0 "/ alkaline earth
oxides 3.25

Glass quality clear clear clear clear

Crystallization heat treatment

° C for (hours) 72O (64) 720 (i6) 720 (i6) 720 (i6)

+
⁰ C for (hours) 1200 (i) 1200 (3) 1200 (3) 1200 (3)

Surface resistance (-Ω-ιΒβ *) after, p-doping for 1/2 hour at ° C

1000 1100

1150 4.3 3.9 4.0 3.9

1200

- 62 -

609827/0828

ORIGINAL INSPECTED

In each of Examples 58 through 63 described above, the nature and appearance of the dopant dispenser before and after doping are essentially the same. There is no collapse or other physical deformation, even with the thin disks of kO mil (1 mm) thick, which made them unsuitable for other planar doping processes.

The previous test results indicate that the

the
Subsidence / invention can be easily formed by Glaskeramikverfallron and can be effectively doped at temperature ¹ s in the amount of 1200 C in structural stability and long operation time. It is also apparent from the foregoing data that the range of components has been expanded and improved over the other embodiments of the invention including Examples 1-57. Examples 58 bis show that a good efficiency in glass melting, glass keramil formation and boron doping can be achieved with a relatively high proportion of SiO and a relatively low proportion of B "0" in order to obtain a controlled strength of boron doping at high temperatures, whereby the tendency to color formation of the doped silicon is kept low because of the accumulation of an excess of boron, which causes an insulating deposit of borosilicide. It is assumed that the BaO content (with or without other alkaline earth components such as MgO) is responsible for this unexpected expansion and improvement of the compositional scope.

- 63 -

6Q9827 / 0828

Claims (1)

Expectations : . yA method for doping semiconductors, characterized in that a semiconductor and a solid doping material dispenser are used to transport gaseous Β _? 0_ are held at a temperature and for a time sufficient to form a p-conductive region in the semiconductor in connection with the gaseous state, -which the doping material dispenser has a glass-ceramic body which is rigid and unchanged in terms of expansion during the doping time,
contains. 2. The method according to claim 1, characterized in that the glass ceramic body contains at least 10 Kol ^c / o B "0" and
is essentially free ν, οη alkali metal oxides. 3. The method according to claim 2, characterized in that the glass ceramic body consists essentially of: component Mol% SiO ₂ 2-50 Al ₂ O ₃ 15-36 ^B 2 ° 3 10-50 MgO 15-36 k. The method according to claim 3, characterized in that the glass ceramic body consists of: - 6k - component 2 SiO ° 3 ^Λ1 2 3 B ₂ O 5-30 20-30 25-50 MgO 2-36 5. The method according to claim 2, characterized in that the semiconductor is an η-conductive silicon semiconductor » 6. The method according to claim 5j, characterized in that the silicon semiconductor comes into contact with an atmosphere which essentially consists of BpO vapors and a carrier gas for the BpO vapors. 7. The method according to claim 5 »characterized in that ο ο the temperature in the range between 700 ° C and about 1200 ° C lies. 8. The method according to claim 7, characterized in that the temperature in the range between '85Ο C and about 1100 C lies. . 9..Das method according to claim 1, characterized in that The glass ceramic dispenser is formed by an on-site thermal crystallization of an original Glass composition that is less than about $ 0.5 mole Contains alkali metal oxides and essentially consists of: - 65 - 60982 7/0 8-2 8 La ₂ O ₃ Mon I-56 1.5 0-15 2545628 component Nb ₂ O ₅ 15-40 0-10 SiO _? Ta ₂ O ₅ 15-30 0-10 ^A1 2 ° 3 20-60 0-10 ^B 2 ° 3 5-25 0-5 RO 0-5 where 4:> ^A1 2 ° 3.> ■ 0-5 RO where RO is: MgO CaO SrO BaO the glass-ceramic dispenser being rigid and bulky is unchanged during the doping at a temperature above about 1050 ° G. 10. The method according to claim 9 »characterized in that the glass ceramic dopant dispenser essentially consists: component MoJU ₁ ^ SiO ₂ 18-40 Al ₂ O ₃ 15-30 B ₂ O ₃ 30-60 RO 5-15 609827/0821 - 66 - where h _2l ^A1 2 ° 3 J> 2 RO where the MgO content in the RO is at least about Is $ 3. 11. The method according to claim 9j characterized in that the semiconductor is an n-conducting silicon semiconductor. 12. The method according to claim 11, i.e., the fact that the silicon semiconductor comes into contact with an atmosphere consisting essentially of B "O" vapors and a carrier gas for the B _{0 O vapors.} 13 »The method according to claim 11, characterized in that the temperature is in the range between about 1050 C and about 1200 ° C. 14. The method according to claim 11, characterized in that the semiconductor and the glass-ceramic dopant dispenser are in the form of thin disks, the dopant disks having a thickness in the region of about 15 to 50 mils ( 0.2 k mm to 1 , 25 mm). 15 · The method according to claim 1 ^ ·, characterized in that a number of semiconductor chips and a number of them glass-ceramic doping matorial disks are set up alternately, the flat disk surfaces in the are substantially parallel to each other and closely opposed to each other with a spacing therebetween. 609827/08 2 8 - 67 - ' 16. The method according to claim 1, characterized in that the glass ceramic dopant dispenser is formed by an on-site thermal crystallization an original glass tisani composition made of barium aluminum borosilicate, the less than about 0.5 moles - * # of alkali metal oxides contains and essentially consists of: component Mol- ^ SiO ₂ 4o <-60 ^A1 2 ° 3 10-30 B ₂ O ₃ 20-40 BaO 1-15 Alkaline earth oxides 3-20 from the group, those made of BaO, MgO, CaO, SrO and Mixtures of these .consists x / obei 4 ^ ^A1 2 ° 3 > * 1, Alkaline earth oxides the proportion of barium oxide being about 1-15 mol-5ε the composition is 17 · The method according to claim 16, characterized in that the glass ceramic doping disk essentially consists of: component Mon 1-% SiO ₂ 40 <-55 Al ₂ O ₃ 10-30 ^B 2 ° 3 20-40 BaO 3-15 Alkaline earth oxides 5-15 where k >, ^A1 2 ° 3 > _ 2 Alkaline earth oxides the BaO content being at least 3 / o. 18. The method according to claim 16, characterized in that the semiconductor is an η-conducting silicon semiconductor. 19 · The method according to claim 18, characterized in that the silicon semiconductor with an atmosphere that is essentially from B O "vapors and a carrier gas for the B_0 vapors exists, comes into contact. 20. The method according to claim 18, characterized in that the temperature is in a range between about 1050 ° C to about 1200 ° C. 21. The method according to claim 18, characterized in that the semiconductor and the glass-ceramic doping material dispenser
are in the form of thin disks. 22. The method according to claim 21, characterized in that a number of semiconductor wafers and a number of glass-ceramic doping material wafers are set up alternately
are, with the planar disk surfaces substantially
are parallel to each other and with a distance between them
to be close to each other " 23. The method for boron diffusion in a silicon semiconductor, - 69 - 609827 / OS2 » characterized in that it includes the following steps: the introduction of at least one silicon semiconductor into a heating chamber, the introduction of a glass core dopant dispenser in the heating chamber, which contains at least 10 MoIi ^ S ,, 0_ and is substantially free of alkali metal oxides, the Doping material donor is in connection with the silicon semiconductor in the gaseous state, without being in direct contact with it zvl ; the heating of the silicon semiconductor and the glass-ceramic doping material dispenser to a temperature between approximately "OO C" and 1200 C for a period leading to the release of the B_0_ » Vapors from the glass-ceramic doping material dispenser are sufficient j contacting the B ₂ O vapors with at least a portion of the surface of the semiconductor for a period of time sufficient to allow the boron to diffuse into the surface of the silicon semiconductor to form a boron-enriched region therein. 24. The method according to claim 23 »characterized in that the silicon semiconductor is an η-conducting semiconductor. The method according to claim 2k , characterized in that the silicon semiconductor and the glass-ceramic doping material dispenser are designed in the form of disks. 2.6. The method according to claim 25, characterized in that a number of silicon semiconductor wafers and a number 609127/0828 -70- alternating of glass-ceramic doping material disks
are arranged, the flat disc surfaces in
are substantially parallel to each other and spaced apart
stand close to each other in between. 27. The method according to claim 25, characterized in that a pair of the semiconductor wafers are in back-to-back contact in a substantially parallel, opposed arrangement at a distance from the flat surfaces of the doping material disks lies. 28. A solid dopant dispenser for transporting BO
in the gaseous Zixstand at elevated temperatures, thereby
characterized in that it contains a rigid, extensively stable glass ceramic pane. 29. The doping material dispenser according to claim 28, characterized in that that the glass-ceramic disk is at least about Contains 10 moles -96 B _{2 O.} 30. The doping material dispenser according to claim 29, characterized in that it has a connection that is substantially
consists: component Mol% SiO ₂ 2-5O Al ₂ O ₃ 15-36 B ₂ O ₃ 10-50 MgO 15-36 609827/0828 - 71 - 31. The doping material dispenser according to claim 29 »characterized in that that it essentially consists of: component UoI- ° / o SiO ₂ 5-30 ^A1 2 ° 3 20-30 B ₂ O ₃ 25-50 MgO 15-36 32. The doping material dispenser according to claim 30 or 3I »thereby characterized in that the glass-ceramic is produced by thermal crystallization on site. " 33 «The doping material dispenser according to claim 28 for the transport of BpO in the gaseous state up to elevated temperatures of over 1050C, produced by thermal crystallization in place of a thermally crystallizable glass composition, characterized in that it is im essential consists of component Al ₂ O ₃ ^Α1 2 ° ·? τ 15-30 i ¹ »5 'B ₂ O ₃ 20-60 RO 5-25 where h _> _ RO - 72 - 609827/0828 where RO is: MgO CaO SrO BaO La ₂ O 3 0-15 0-10 0-10 0-10 0-5 0-5 0-5 34. The doping material dispenser according to claim 33> characterized in that that it essentially consists of: Component Mol - '/ o SiO 18-4O Al ₂ O ₃ 15-30 B ₂ O ₃ 3O-6O RO 5-15. · ..- ■■■ where 4> ^ ^A1 2 ° 3>; 2
RO where the MgO content of the .RO is at least ^ ⁰ Jo . 35 · The doping material dispenser according to claim 28, characterized in, that the glass ceramic is thermally crystallizable in place by a thermal crystallization CFI composition is produced that essentially consists: . - - 73 - 609827/0228 Mol- # 2545628 component 4o <-60 SiO ₂ 10-30 ^A1 2 ° 3 20-40 ^B 2 ° 3 1-15 BaO 3-20 Alkaline earth oxides
from the group,
those made of BaO, MgO,
CaO, SrO and
Mixtures of these
consists > 1.5 4> Üs ^ Alkaline earth oxides the BaO content being about 1-15 MoI-Jo of the composition amounts to. 36. The glass ceramic doping material dispenser according to claim 35 »characterized in that it consists essentially of: component Mol% SiO ₂ kO < -55 Al ₂ O ₃ 10-30 ^B 2 ° 3 20-40 BaO 3-15 Alkaline earth oxides 5-15 where k > ^A1 2 ° 3 > 2 Egg alkali oxides
where the BaO content is at least 3 ^c / o , 37 · The glass ceramic doping material dispenser according to one of Claims 28 to 36, characterized in that it has the shape
a thin slice. 609827 / Q828 Blank page