DD141378A1 - METHOD OF GENERATING DOTED LAYERS IN SOLID CARBON SURFACES - Google Patents

Abstract

Process for producing doped layers in Solid surfaces, preferably in semiconductor and Insulator thin films. The aim of the invention is, as possible simple, inexpensive way the introduction of foreign atoms in To enable solid surfaces. This leads to the Task from, with comparably low expenditure on equipment atoms in Deposit solid surfaces without generating radiation damage. According to the invention, this object is achieved in that the doping atoms pre-deposited on the solid surface or suitably gaseous between sample and a laser source to be brought. The sample is subsequently followed by a laser pulse irradiated appropriate energy density, so forms a shock wave which causes the penetration of the Freradatome in the solid. Due to the simultaneous short-term heating of the surface the atoms are preferably stored in lattice sites. The invention is applicable in the manufacture of semiconductor devices and optical thin film arrangements.

Description

(Title of the invention

Method of producing doped layers in plaque body surfaces. , , ·

Field of application of the invention

The invention relates to a method for producing doped layers in plague body surfaces, in particular semiconductor or insulator thin films. The invention can be used both in the production of semiconductor components and in the production of optical components in which the doping of near-surface regions is important.

Characteristic of the known technical solutions

A known method for doping semiconductors is to shoot ions with accelerators in the surface thereof. This method known by the term ion implantation is disadvantageously associated with high expenditure on apparatus. A considerable disadvantage is the partial destruction of the crystal lattice. In order to eliminate the damage which has an influence on the properties of the semiconductor components, heat treatments are required. Another disadvantage of the method is that the doping elements must be ionized before acceleration "This is possible with some dopants only with considerable technical expense. Also, a disadvantage of the method v / consider that implantation can only be done under high vacuum conditions *

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Object of the invention. ·.

The aim of the invention is to enable the introduction of premodromes into plague body surfaces in the simplest possible and cost-effective manner.

Explanation of the essence of the invention

The invention is based on the technical problem of developing a method which makes it possible to store atoms in the surface of the plague body without undesired side effects and with comparably low expenditure on equipment.

According to the invention the object is achieved in that between the surface of the plague body and a laser source, the atoms to be introduced are preferably brought into a gaseous state of aggregation. Thereafter, in a suitable manner, a laser pulse is directed through the gas onto the sample surface such that a shock wave is formed in the gas. This causes the acceleration of a portion of the ionized atoms towards the plaque surface into which they penetrate. The sample surface is simultaneously heated by the laser pulse in such a way that the introduced atoms are stored mainly at lattice sites. , '

An expedient embodiment is to bring the doping elements in gaseous or in gaseous connections between the laser source and the plague body. The choice of gas pressure allows the storage concentration to be determined. '

According to the invention, however, it is also possible to pre-deposit the dopants as a layer of liquid or plague on the material to be doped, or to deposit it in the region of the pix of the laser beam in front of the surface of the sample.

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The incorporation of the foreign atoms and their distribution can be influenced by choice of the plague body temperature. Depending on the desired doping, several types of atoms can be introduced simultaneously or successively. For the generation of large-area dopings or doping structures, the sample surface is scanned with the laser beam in a suitable manner according to the invention ^; However, it is also possible to produce masks on the plague body or between the laser source and solid body for the production of doping structures. It is also possible for the laser beam to image a mask appropriately.

embodiment

The invention will be explained below using an exemplary embodiment.

According to the method, a solid sample is brought into a chamber which, after evacuation, is filled with a gas of the desired dopant. Depending on the concentration of the atoms to be introduced, the pressure is selected. Thereafter, the pulse of a solid-state laser, e.g. ruby laser, is sent to the sample through the gas. The energy density per pulse

can e.g. On completion of doping, the chamber is evacuated again, if necessary, and filled with a second doping gas, and the process is repeated.

Depending on whether a Vorablage on the sample surface or during the laser bombardment the vapor between the laser source and the sample should be located, the vapor flow is limited by suitable diaphragms for not or only gaseous available or manageable atoms in the chamber ,

The energy density on the sample and the location of the doping is determined with a suitable optics known per se.

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In a "particularly expedient embodiment, the sample holder consists of a heatable cryostat finger on which the sample temperature can be predetermined." The advantage of the method according to the invention is that no radiation damage occurs compared to ion implantation Nuclear species with relatively little technical effort in Pestkorperoberflaohen can be introduced,

Claims (11)

Claim of invention . 1V method for producing doped surface areas in solids, characterized in that atoms or molecules of a medium between a laser source and the solid state • Body is brought and then a laser pulse is sent through the medium on the plague body 'that are introduced by a shock wave generated by the laser beam, the atoms in the plague surface at , simultaneous near-surface warming of the plague body » , 2. The method according to item 1, characterized in that the. Medium is gaseous. 3 · Method according to item 1, characterized in that the. Medium is liquid » 4 «method according to item 1, characterized in that the." Medium is fixed. · 5. The method according to item 1 to 4 characterized by,. that the plague body is cooled. 6. Method according to item 1 to 4 characterized by,. that the plague body is heated. 7 · Method according to item 1 to 6, characterized in that the laser beam pointwise over the solid state. surface is moved «· 8 «: Method according to item 1, characterized in that. different types of atoms are introduced in succession. 9 * Method according to item 1, characterized in that:. different types of atoms are introduced at the same time «, 10. The method according to item 1, characterized in that on the plague or between the plague and the laser source. Masks are brought. · 11 · Method according to item 2, characterized in that. the amount of ion introduced is predetermined via the choice of gas pressure. '.