DE1544200C3 - Process for the production of semiconductor bodies - Google Patents

Description

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in the area of 1.25 μm, 1.6 μm and 2.25 μm. With renation reaction are known per se and these procedures should therefore not be further localized in this context Transitions from high to low temperatures are explained in detail. It is in the present probe can be carried out, as with the previous example, essentially about the fact that the disknowed Procedure was possible. 5 proportioning reaction of the transport of mate-This object is achieved according to the invention by a rialien in the form of iodides in the vapor phase (iodine Process for the production of semiconductor bodies with- is the means of transport) of which a certain Temtels Gas transport reaction in a source material having source and germination temperature to one elements containing vacuum vessel dissolved, with lower temperature having receiving subdie to carry out the procedure in the area of the io strat.

The process temperatures according to the invention by heating the vacuum vessel are carried out with the aid of the methods shown in FIGS. 1 and 2 represent and / or through locally different heat-provided arrangement. The arrangement consists in adjusting the supply. What is essential according to the invention from a reactor consisting of quartz is characterized in that the setting chamber 10, which has a semi-cylindrical shape, also has a straight wall 12 for the local temperatures. At the end of the controllable heat dissipation via heat sink chamber 10, a transparent quartz wall 14 is attached, welded, which closes the chamber in this direction and forms an observation window. The method according to the invention is characterized in that the opposite side of the chamber is originally characterized in that, when using III-V compounds ^οίϊεη > so that the various substances that are responsible for the vacuum vessel to a temperature between. ^the - growth process are required, introduced 750 and 900 ° C is heated. can be. The chamber is evacuated and sealed to another particularly advantageous feature of ^{this side with} a quartz plug 16, as from the method according to the invention is that 25 ^{fl 2} can be seen.

the temperature of the surface to be coated ^The reaction chamber 10 has two temperature seed crystals after the start of the transport process, which are formed by the fact that under and occurrence of a condensate is set, serving as the bottom part of the straight wall 12 of the that the deposited Layer has a uniformly glossy chamber two metal blocks 18 and 20 arranged zende surface. 3 <> smd, which serve as tub sinks 1. The tub sinks Then the invention on the basis of JJ and 20 are supported by bands 19 and 21. Figures explained in more detail. It shows the heat sinks are preferably from a fig. 1 as silver produced which has the perspective view of an appA f ^ th ^ a good Warmeratur to KriLllwachsen conductivity according to the invention and communication with the contemplated

2 shows a longitudinal section through the chamber, which is not damaged at 35 mend temperatures,
part of the apparatus according to FIG. 1 forms, ^D £ heat sinks 18 and 20 have Ausnehmun-F ig. 3 the schematic representation of an Injek- ^ ² I for the passage of liquids, to the Flus- .. f. , -OJCCJ fluid lines 24 and 26 are connected, with tion diode according to the invention ■ whose help a coolant, for example air, to Fig. 4 diagrams the _nd the range of 4 ° ₂₄ ^S _u generated by ^ ^ Flüssigkeitsleitunspontane and stimuherte emission _{26 are d th Vorric} | _{t represent the} radiation of a diode according to the invention. l _{ufrechterhaltung an} ^S coolant circulation verbun-F1 g._5 the schematic representation of the correlation _{of the} ^ ^ ^. _{24 connected} device tion between the radiation wavelength and the supply _{zuf AufrechterhaItung} * _{of the circulation is} independent of the invention _VQN composition of diodes according to _{the the Ld} £ _associated device, so the appearance of spontaneous and stimulier- 45 _{that various Temp} eraturen to the heat ducks radiation emission can be maintained in different _{halves of keQ 18 and 20, those} close to the ladder mat can be observed. One of the monitors for the ascent _by temperature sensors 28 and 30 of this phenomenon value-free Eigenschaf- required _{to this Au} f _{reproducing wu} d in th in Fig. 1 and 2 of a semiconducting material is the presence in devices shown by thermocouples form of homogeneous crystals of high quality- 5 <> ^. ^ _{di &} ^ _metallic heat sinks touch tat and perfection. According to the invention _and suitable devices, not shown, are given the means and methods by which semi-connected _to register the temperatures, conductive compositions of the elements of the third Dj ₆ heat sinks 18 and 20 and their associated and fifth valence groups can be Mendeleeffschen _Neten temperature control and display devices, the periodic system in form of single crystals of the 55 enable AufrechterhaItung two areas grown with which the spontaneous _m j _t variable temperatures can be realized within and stimulated emission. With the help of chamber 10. The drain 18 of the associated region of these means and methods have been new homogeneous _se j _e in the deposition area and the valley 20, single crystals of good quality and controllable adjacent region is a source substance area. Composition in the system In (As _x P _1. *) Produced. 60 inside the chamber, directly above the heat-the inventive method for manufacturing sink 18, a substrate 32 is arranged on which the crystal according to the invention is grown by a gas crystal. Above the sink, the transport reaction is realized, at which, at temperature, pieces 34 and 36 of the source material are put on, which are lower than the melting temperatures.

of the elements involved are elements through a 65 order the growth of a single crystal of high quality To ensure disproportionation reaction of a source material and perfection, the subrial must be deposited on a support. The base strat 32 must be carefully prepared. It's from The vapor growth and the disproportion were of great importance that the substrate 32 itself

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A single crystal is cut along a crystallographic area of about 0.5 to 5 mg in a chamber of about 5 surfaces, so that a ^{receiving area of about 4 lying in the desired or 6 cm 3} content in the crystallographic plane is an impurity concentration. 10 ¹⁹ carriers per cm ^3; Crystal generated.
33 is formed. ' The substrate does not have to be taken from the As a means of transport, highly pure iodine is used as a substance similar to the substance to be grown on it. Because of the low melting point, this stall should be made of a material, but during the evacuation of the chamber, which has a similar lattice structure as the mer 10, care must be taken to ensure that it does not contain any crystals that are to be grown. steams. To avoid this, the chamber 10

As particularly suitable for carrying out the he by means of a vacuum pump (not shown) before the

According to the inventive method, substrates 10 have evacuated the introduction of iodine. The iodine is in

from indium arsenide single crystals. This sub- housed a special vessel, which also

strates are cut from monocrystalline blocks, with the vacuum pump through an originally

which was previously connected with the help of X-ray technology.

ren were aligned in the crystallographic After the chamber 10 EVA to about 10 ^-7 Torr

's surface (100) receiving surfaces lying was kuiert to ER- _15, the suction pipe from the pump is

keep. The receiving surface of each substrate is removed and the valve that connects to the

32 is controlled using a glass plate and an iodine container is opened. The iodine container

Polishing made of silicon carbide, for example, is so small that the air it contains is the

by means of a grain size of about 40 μΐη polished kuum no further than reduced to 10 ~ ⁴ Torr. To-

and then with the help of an alcohol _{bromide 30 from} which the iodine container was evacuated, it is in

mixture immersed in a grain size of 0.1 μm on liquid nitrogen in order to sublimate the

pointing polishing paper finely polished. Avoid iodine and the pumping will be up

The donor-source material or elements 34 to achieve a vacuum of 10 ^-7 Torr in the and 36 are in the form of blocks, which all continued chamber. The chamber is then included in FLÜS elements sigen in the ₂₅ to be grown nitrogen and immersed Jodbehälter crystal is to be combined. When growing slowly heated so that the iodine in the chamber 10 crystals of the system In (As _x P ₁ ^.) Blocks are transferred by distillation. Then used from InAs and InP. The blocks can be the plug 16 for the purpose of sealing the kampolycrystalline and do not have to be welded along the mer and the connection with the vacristallographic axes cut. It has kuumpump is interrupted. It has of course also been shown that the composition of the grown crystal is possible, other methods known per se, depending on the size of the substrate in the reaction chamber facing the substrate to be used for introducing the iodine into the chamber.
Faces of the blocks. After the reaction chamber has been loaded, eva-

It appears that the etching was kuiert to the source and sealed, the heat sinks are materials, primarily Instead of these surfaces ³⁵ fixed to their seats, and the whole apparatus takes place, although the upper and side surfaces in an oven, e.g. be etched in a furnace 38 to some extent. The combination of the in FIG. 1 shown, underlain between the size of the germs brought. The oven is closed and sealed, but the facing surface is so strong that you can avoid undesired air currents around the chamber way of the composition to tolerances of ⁴ ° 10. Sealing the oven makes a few percent that can be determined. The areas 35 have a view through the window 14 required for observation of the interior of the and 37 of the source substance blocks 34 and 36. The afterwards cut so that they are in proportion to the perspective, for example, by a desired quartz composition of the end product plate on the left side of the furnace 38 is made possible. For example, ⁴⁵ will be for a crystal.

In (As _{0 5} P ₀₅ ) the size of the areas 35 and 37. The growth process is chosen by heating the same. If an In (As _{0 2} P ₀₈ ) crystal is to be produced in a furnace at a temperature of about 830 ° C., the blocks 34 and 36 are cut in this way. During the heating process you will th that the size of the surfaces 35 and 37 in the ver that the interior of the chamber is initially the ratio 2: 8. The source material blocks 34 and ⁵ ° violet color of the iodine and then the yellow-36 are assumed with the help of glass plates and a borrowed color of the indium iodide.
Polishing agent, consisting of silicon carbide with a while the temperature inside the chamber polishes grain size of about 40 μΐη and grows with one, the cooling devices for the alcohol bromide solution are cleaned so that all heat sinks 20 are actuated to keep the temperature in the surface regular and free of foreign substances 55 Reduce the source area. The flow of cooling are. They are then controlled in the chamber 10 directly by means of is controlled so that the temperature of the swelling area above the heat sink 20 with the surfaces 35 and 37 is about 100 ^° C. below the ambient in the direction of the germs. . temperature is. The deposit area will not

The crystals grown in the reaction chamber are substantially cooled. ^{It may be doped by a} few degrees below the ambient furnace temperature at the same time during growth, so that it is necessary to keep an amount of doping material in the chamber appropriate to the possibility of positive control. tion in both directions. The source and the doping material is selected according to the desired material area is therefore cooled in order to avoid contamination of the crystal. To know the transport of vapor from the seed to the swelling growth of η-conducting crystals, a small material has to be brought about, whereby the surface 33 is cleaned of tellurium or from other η-dopants and to ensure that any substances like selenium, Silicon, etc., introduced into the chamber which undesirable at low temperatures. For example, through a large number of reaction products formed in the swelling area

are condensed and do not poison the germ. If the temperature rises above about 500 ° C, so the structure of the upper surface of the germ changes and becomes very shiny. This change in appearance occurs as a result of the surface being etched by iodine vapor. This etching of the germinal surface cleans use them as preparation for subsequent deposition and was found to be necessary for growth of a good quality crystal. During the etching process on the surface of the germ begins facing the source area, the surface 33 is etched enough so that it is cleaned before the front is significantly eroded.

The pre-etching process does not take much time and can take about 10 minutes or after the surface of the germ has achieved a uniformly shiny appearance, are considered complete. The process will generally be finished when the furnace has reached 800 ° C. At this point in time, the supply of coolant to the heat sink assigned to the source area is stopped so that this range approaches the oven temperature to within a few degrees. To this At this point, the coolant is passed through the heat sink 18 in the deposition area of the chamber 10, to cool this area. As the temperature in the swell area increases, it becomes considerable Etching process on the source blocks 34 and 36 observed.

So much coolant is now passed through the heat sink of the deposit area that the Temperature in this area below the dew point of the iodides in the chamber sinks, which results in the formation of condensate on the surface of the germ. When this takes place the coolant flow is carefully reduced in order to slowly increase the temperature to allow in the deposit area. After exceeding the dew point temperature, the condensate is disappear on the germ 32. These temperatures, which are within small limits due to certain Differences in the dimensions of the source material and the doping concentrations, etc., vary can, can with sufficient certainty by reading the temperature of the heat sink 18 to The time at which the condensate disappears can be determined.

Now, the temperature of the deposition area is allowed to slightly (about 5 to 1O ⁰ C) over the specified dew point and then increase the flow of coolant is adjusted such that this temperature is kept constant. This temperature is significantly below the temperature in the swelling area, as can be seen from the third and fourth columns of Table I. Under these conditions, the growth of a single crystal is observed on the seed, the composition of which is determined by the dimensions of the source material blocks and which is doped with the intended substances. If the boundary conditions have been set correctly, good uniformity of growth is observed. The quality of the crystal can be visually determined when there is a uniform shiny growth over the entire surface of the seed. If conditions occur which hinder the growth process, which is noticeable, for example, in the occurrence of condensate or the growth of isolated crystals, then small compensatory adjustments to the temperature of the deposition zone can be made by controlling the coolant. At times it may be necessary to swap the temperatures in the two areas mentioned so that the growth process is reversed and parts of the crystal that have grown incorrectly are removed. This can be done with the inventive

Apparatus can be carried out easily. After removal of said substances become the original growth conditions, as further described above, restored.

At the end of the growth process, which after about

5 to 20 hours for a single crystal of about 0.5 mg, the energy supply to the furnace is interrupted and the system cooled down. At this point, the coolant is circulating in the heat sink decreased so that the temperature in the deposition area approaches the temperature of the chamber. The heat sink 20 assigned to the source area is supplied with enough coolant that this area is cooled much faster than the other parts of the system. By this measure the termination of the growth process on the germ is ensured and causes all that are still present Reaction products are deposited in the swelling area, so that a poisoning of the grown Crystal is excluded.

The boundary conditions and details of a number of experimental growth processes of single crystals of the best quality are listed in Table I. From this table it can be seen that any desired composition of the form In (As _x P _1-1 ) can be realized in the form of a homogeneous single crystal of the best quality.

Table I.

copy composition temperature
of
Source material temperature
of
Carrier concentration
the doping resistance
of the crystal Hall
constant MRM 18 InAs Te-3.9-10 "» 9.73-10- * 0.161 MRM 19 In (As _{0 82} r ₀₁₈ ) 820 ° C 76O ⁰ C Te-2.3-10 " 9.74-10- « 0.273 MRM 20 In (As _o, P _{85 n. 15)} 840 ° C 76O ⁰ C Te-3,3-10 »· 22.6 -ΙΟ- ⁴ 0.192 MRM 21 ^In ( ^As 0.51 ^P 0.49) 820 ° C 785 ° C Te-1,4-10 »· 5,79-10- ⁴ 0.441 MRM 23 In (As _0i79 P _0i21 ) 825 to 885 ° C 76O ⁰ C Te-2.6-10 " 13.7 -ΙΟ- * 0.230 MRM 24 ^OK ( ^AS 0.87 ^P 0.1 ₃ ) 835 ° C 700 ° C Te-1,8-10 »> 1.66-10-4 0.336 MRM 25 ^In ( ^As o, 84 ^P n.ic) 86O ⁰ C 78O ⁰ C Te-2.2-ΙΟ " 6.34-10- " 0.281 MRM 26 In (As _{0> 4I} P _{0. M} ) 82O ⁰ C 72O ⁰ C Te-1,4-10 »· 2.26-10- " 0.445 MRM 28 ^In ( ^A S ₀ .18 ^P 0.S ₂ ) 820 ⁰ C 605 ° C Te-6.8-10 ¹⁸ 6.65-10- " 0.918

ίο

In all of the growth processes listed in Table I, the conditions described above were used maintain. The distance of the seed to the source material was changed slightly but always less than 2V2 cm. This distance incidentally, was not found to be particularly critical. As shown above, there is only one whole general determination of the dopant concentration when the dopant is free in the chamber 10 is located. If more precise control of this process is desired, a crystal can be used with the help of grown from a pair of source crystals, one of which beforehand in a certain way was endowed and the other is undoped. By changing the dimensions of the doped and the undoped source crystal, any desired doping concentration can be achieved.

The crystals produced according to the invention can be used in a manner known per se Diodes are made. A particularly advantageous method for producing a diode according to F i g. 3 made of an η-doped crystal will be described below.

The seed with the homogeneous single crystal layer grown on it is first produced with the aid of a X-ray diffractometer adjusted so that it runs along the. crystallographic (100) plane sectioned can be. The crystal is cut and polished along this plane to one of flaws and Disturbances to get free space. This area becomes area 40 of the finished diode. After polishing the crystal is washed, dried and prepared for the diffusion of an interface.

For diffusion, the crystal is melted in a quartz container in which a small amount of zinc arsenide, for example 2 mg for a container of 6 cm ³ capacity, is accommodated, and which is then ^{evacuated to about 10 ~ 7} Torr. The container is then heated in an oven to about 650 ° C for a period of about 2 hours. During this time, the zinc diffuses into the crystal from all sides, including the polished surface (100), and creates a p-conductive layer in the η-conductive crystal.

As in Fig. 3 indicated by the reference numeral 42, is parallel to the (100) plane between the puhd the η-conductive area at a distance of about 25 μm an interface is created from the polished surface.

After the diffusion, the crystal is cut,

to get a flat surface along the (100) plane on the side of the crystal opposite to the original ground surface. This area becomes area 44 of the finished diode. The grinding process is carried out until all traces of p-conductive Material are removed and the distance between the two opposing faces is up about 120 μΐη is set.

After grinding, the crystal, which is now available as a 120 μm thick plate, is washed again and dried and with metallic ohmic contacts 46 and 48 on those in the (100) plane lying surfaces 40 and 44 in a manner known per se, for example by currentless Deposit, provided.

It is desirable that the finished diode have end faces 50 and 52 that are perpendicular to the Interface and are optically flat and parallel to each other. The purpose of these surfaces is to provide a Part of the radiation generated in the area of the interface to reflect and the emission in and for to reinforce in a known manner. While these surfaces are created by grinding and polishing it is especially beneficial to split them by splitting them

of the crystal along a crystallographic (HO) plane to create. The plate is split so that the distance between the two lying in a (HO) -plane Areas is about 400 μπι. The two side edges 54 and 56 of the finished diodes are through

Saws generated.

The in F i g. 3 illustrated finished diode is provided with electrical leads 58 and 60, which with the ohmic contact surfaces 46 and 48 are connected and are used for the injection of carriers.

The diodes produced by the method specified above are used as radiation-emitting arrangements into which current is injected via the electrodes mentioned and a power source 62. Spontaneous radiation emission was achieved with these diodes at injected current densities of not more than 525 A per cm ² at a temperature of 77 ° K and 600 A per cm ² at room temperature.

Excited emission, or rather laser activity, is normally achieved with current densities of no more than 6000 A per cm ² at temperatures of 77 ° K. Both spontaneous and excited emissions were achieved in the absence of any electric fields.

Table II

Diode
temperature Current density Spontaneous Emissior 1 Line width Current density Excited emission Line width copy A / cm ² Max. Lines
wavelength μπι A / cm ² Max. Lines
Wavelengths μπι 77 ° K 1050 μπι 0.24 μΐη MRM 18 77 ° K 2820 3.25 0.12 MRM 19 4 ° K 3300 2.27 0.08 MRM 19 4 ° K 2400 2.23 0.13 MRM 20 300 ° K 600 2.47 0.18 MRM 21 77 ° K 525 1.71 0.06 15,400 0.0023 MRM 21 4 ° K 4000 1.61 0.02 2,500 1.60 0.0051 MRM 21 2 ° K 1.59 620 1.59 0.0004 MRM 21 4 ⁰ K 1200 0.09 1.59 MRM 23 4 ° K 3900 2.19 0.14 MRM 25 77 ° K 1500 2.33 0.05 14,700 0.0064 MRM 26 4 ° K 1.44 35,600 1.44 0.0052 MRM 26 1.43

Table II gives details of crystals grown by the process according to the invention assembled diodes. In Table II, the left column contains information about the Crystal specimen from which the diode was made. Table I gives details of the growth process of the specimen in question.

In all of the above specimens, the spontaneous emission was shaped by current injections of pulses with a length of 10 μβ and one Repetition frequency of 500 pulses per second generated.

Excited emission was observed in all experiments with the sample MRM 26 and in experiments with 77 ° K with the model MRM 21 through the injection of current pulses with a length of 50 ns and a repetition frequency of 60 Hz. When testing at 4 ° K and 2 ° K with the specimen For MRM 21, pulses with a duration of 500 ns and a repetition frequency of 100 Hz were used.

From Table II, the wide range of wavelengths can be seen, which with according to the invention Process manufactured diodes can be achieved. Though not excited in all cases Emission could be generated, but it can be seen that a laser function in a very wide range can be determined.

It is also pointed out that the laser beam emitted by the diode from the material MRM 21 was produced, has an extremely narrow bandwidth at 2 ° K. after the The wavelength of this material corresponds to that of a so-called atmospheric window in the infrared range, it can be assumed that this composition is of particularly great importance.

It should also be noted that the diode MRM 21 spontaneous emission at normal current densities and at room temperature. This property was not found with any of the known arrangements realized so far.

The emission characteristics of the diode MRM 21 at 77 ° K are shown in FIG. It should be noted that the curve 64 representing the distribution of the emission has the characteristic bell shape having. The line width of the spontaneous emission is about 600 Α units. If the threshold the excited emission is exceeded, the line width narrows very strongly (up to about 23 Α units), as indicated by curve 66, while the maximum intensity increases sharply.

In Fig. 5 the maximum wavelengths of the various grown according to the invention Crystals shown. As can be seen from the figure, there is a very complete spectrum of wavelengths between the InAs and InP wavelengths to the Disposal. Any desired wavelength can be selected according to the invention by adjusting the ratio As can be achieved to P in a crystal grown according to the method according to the invention.

1 sheet of drawings

Claims (2)

1 2 claims not necessarily influenced by the presence of other similar photons. With larger ones 1. Process for the production of semiconductor densities of the supplied pump energy is this Ab-> bodies in a dependency by means of a gas transport reaction but getting bigger, which leads to a source of and seed elements containing vacuum constriction of the emitted bandwidths and to a vessel, where the implementation of the process improvement of the coherence and the directional bundling rens in the area of the substrate and the source sub- leads. Punch required temperatures through spontaneous and stimulated emission can be set locally different heat supply with half heating of the vacuum vessel and / or through conductive bodies by injection of minority carriers through a pn boundary layer in the forward direction and that, characterized in that it is generated in a suitable density will.
Adjustment of the local temperatures. Additional spontaneous and stimulated emissions were previously achieved with various III-V compounds, such as gallium, caused by controllable heat dissipation via heat sinks. arsenide, indium arsenide, indium phite, gallium 2. The method according to claim 1, characterized in that 15 arsenide phosphite and indium gallium arsenide are observed, that when using Ill-V-Vertet. The radiation from these compounds lies in the bonds the vacuum vessel, to a temperature range of the wavelengths of less than 1 [xm. door is heated between 750 and 900 ° C. In the German patent specification 1 029 941 a ■, 3. Method according to claims 1 and 2, method for producing semiconductor single crystal characterized in that the temperature of the 20 layers is described at which before the implementation of the Areas of the seed crystal to be coated, after the reaction, first an etching polish and then Start of the transport process and the occurrence of cleaning of the substrate to be coated a condensate is set so that the evaporation or atomization in a high vacuum A uniformly shiny upper layer is made on the stored layer. The evaporation and atomization has surface. ² 5 Practice cleaning is carried out in the reaction vessel itself. taken. The during the evaporation and atomization necessary temperature changes during The invention relates to a method for production carried out exclusively by controlling the position of semiconductor bodies by means of gas transport reaction heat supply. This has the disadvantage that a vacuum vessel containing swelling and seed elements only increases the temperature quickly, which can be used to carry out the mixing, while lowering the temperature in the area of the substrate and the swelling substances only through slow, gradual cooling Required temperatures can take place by heating the entire device. The provision of the vacuum vessel and / or locally the same applies to German patent specification 1,152,197, different heat input can be set. 35 which is a very special method for transferring the radiation-emitting components, in particular on a plane to be coated, has been related to the development of the substance of a platelet containing source material in recent years,
the development of so-called lasers, particularly I _n German Patent 1124 028 and operated in intensive. In contrast to this device, the German Auslegeschrift 1 159 407 describes cavities that drive due to excited radiation emission 40, in which the ablation or work, the devices with spontaneous vapor deposition due to the setting very specific radiation emission do not have such good coherence and Mo conditions of the gas nochromasy causing the transport; However, these properties are mixed and not by repeated change to an extent which these devices of temperature distribution are effected. These methods of processing messages and passing messages are not suitable for generating transmission over short distances. conductor bodies, as they are with the invention The above phenomena presuppose a process that can be produced
Artificial distribution of electrons on energy In the IBM Journal of Research and Development, levels ahead of the natural distribution 4 (1960) 3, pp. 288 to 295, a method is used to deviate. This artificial distribution is described by the 5 ° epitaxial growth of silicon on a substrate, the supply of a so-called excitation or pumping strate by means of a transport reaction, whereby energy is produced and leads to the fact that the proportion of the being pointed out that one is greater by high energy states occupied by reverse as the initiation of the deposition reaction is a transport of the part of the occupied low energy states. The substrate can force in order to be able to achieve a pure substrate before the actual electrons from the higher than normal energy deposition, levels go within a certain period of time even if this literature reference suggests that the subject is their normal energy level, which would be suggested in each case that the equilibrium of a photon is emitted. Reaction once to one side and once to the other. In the case of spontaneous emission, the photo can be shifted to the other side, it is emitted inconsistently with this tone, so that the resulting process is not possible, in certain areas there is fluorescence low bandwidth to cause rapid temperature reductions,
has, but is still much broader than the The invention has the task of a method for radiation with excited emission. To indicate the distribution of the production of semiconductor bodies, in the case of radiation intensities, a Gaussian reproduces spontaneous and excited emission with a wave-bell curve, the half-width of which is 65 in the range of the so-called »atmospheric line width of the radiation. Windows «, these are areas in which a transfer, as already said, is possible with spontaneous emission under particularly favorable circumstances. Such areas are for example