DD155569A1 - PROCESS FOR HOSTING ELECTRONIC COMPONENTS ON OXYGENIC SI SUBSTRATE DISCS - Google Patents

Abstract

The invention relates to a heat treatment of Si substrates with oxygen contents> equal to 6.10 high 17 cm high -3 with the aim of near-surface slice areas of high structural perfection and chemical purity and inner volume areas with getterwirungsem oxygen-coupled defects - mainly Praezipitaten - to obtain. For the realization, a heat treatment in the temperature range 900 <equal to T deep o <1300 degrees C is performed and a second in the temperature range 600 <equal to T deep u <equal to 900 degrees C, to which, depending on the device technology and Si substrate material optionally further Heat treatment can be connected. Waermebehandlungen in this order make it possible to realize the above objective in relatively short (a few hours) and thus economically favorable time periods. An increase of the component yield is achieved by (1) improvement of device parameters (defect reduction in near-surface substrate regions, volume gettering). (2) Additional increase in the number of usable chips or components due to reduced wafer distortion. (3) Greater lateral and vertical homogeneity of devices Characteristics influencing substrate parameters over the individual disc and within a range of discs.

Description

-ι-- 22 63 8 p

Title of the invention:

Method for increasing the yield of electronic components on oxygen-rich Si substrate wafers

Field of application of the invention:

The invention relates to a method for improving properties in near-surface regions of Sl substrate wafers

* l 7 «-3 with an oxygen content ^ - 6 · 10 cm by controlled defect suppression in a near-surface layer and an internal gettering effect» The method is applicable for both bipolar and bipolar technologies in the production of electronic components ·

Characteristic of the known technical solutions:

In the case of single-crystal, dislocation-free Si substrate material for the component industry, there is a tendency to keep the impurity level as low as possible (u _e a _o use of ZF-matterial) and thereby suppress microdefects, impurities (z "B", / fast diffusing Metal atoms) and microdefects (z _e B "precipitates and stacking faults) with negative effects on specific device parameters are inherently particularly disadvantageous in near-surface disk areas" Certain microdefects, such as oxygen-coupled precipitates and secondary defects (z, B. punching loops), have However, at An ~ settlement in disk volume, so outside of electrically active areas j because of their Getterungseffektes (intrinsic-evacuation in the volume., In the following Volumengetterung called) and the associated improvement of certain device parameters proved favorable / 1 ^ 2 /. The cheapest option for producing

22 63 89

To supply such micro-defects, a two-stage heat treatment is indicated, wherein the second heat treatment takes place in a higher temperature range than the first / 3 /.

Other variants of the invention, which are used prior to the first oxidation and which are intended to effect a cleaning of the electrically active regions during subsequent process steps of the component production, are based on the introduction of impurity sinks on the back of the pane, essentially in the form of locally limited stress fields on ( a, B * Si-JiI,) or implanted (z _c B _e by means of argon ions) layers or defects (ion implantation), Misfitversetzungen due to phosphorus diffusion, mechanical disturbances and dislocations due to lapping, sandblasting, etc. _e / 4 / _e These methods are for , T. apparateteohnisoh consuming and thus costly (ion implantation), ζ. T. associated with unwanted secondary disturbances due to dislocation propagation (sliding) to the front of the disc (penetration into electrically active areas, disc distortion), the latter especially in mechanically induced back defects / 5 / In addition, in Si material with high oxygen content 1 7 -3

from> 6. 10 'cm limits the effectiveness of these external getter methods.

Soheiben warping is also caused by oxygen-coupled precipitates near the surface / 6,7 /. In the case of a large disk diameter (> 76 mm), in component process steps such as oxidation, epitaxy, etc., in addition to an increased activation of displacement equations in the edge region, the excitation of additional sources (induced by acid precipitation) in the central disk region (compressive stress state) is particularly critical. since this is where the active substance is deposited and escapes, preferably at the concave side of the disk / 7 / "This undesirable effect also occurs in principle in two-stage heat treatment of the kind described in the literature / 3 /

Aim of the invention;

The aim of the invention is to increase the yield in the production of electronic components on the basis of Si

17 3

Substrates with oxygen contents> 6. 10 cm by simultaneous realization of a

- 3 - 22 b 3 ö 9

(1) Improvement of device parameters due to creation of structurally and chemically close to perfect near-surface (= electrically active) regions and maintenance of such regions at critical high temperature steps of device fabrication '

(2) Reduction of potential sources of dislocation in the most vulnerable surface areas (front and back of substrate disks, disk edge) and consequently also reduction of disk distortion associated with dislocation formation and movement *

Explanation of the essence of the invention:

The object of the invention is to realize the properties of substrate disks mentioned in the aim. "According to the invention, this is achieved by a heat treatment of substrate disks to obtain defect-deprived surface areas and acid-precipitated voila precipitates. Because of the suppression of oxygen-coupled precipitates in near-surface soy disk areas, they become critical at the same time Reduced dislocation sources and thus avoid additional disc distortion, is generally assumed by a first heat treatment at temperatures T _Q in the range 900 ^: T _Q : $ 1300 ⁰ C, followed by a second heat treatment at temperatures T _u in the range 600 ^. T _u ^. 900 ⁰ C ansohließt "The conditions such as temperature, time, and medium for heat treatments at T lind UL v / ground in response to the oxygen outlet concentration and other real structure of the Si substrates selected so that only sufficient oxygen depletion near the surface either sufficiently potential nuclei for oxygen-coupled precipitates in the volume for further growth during a second :; Heat treatment at a lower temperature T _{u be} maintained or during this second heat treatment again precipitate imaging uses * As the medium oxidizing, reducing, inert and those with surface-active additives such as HGl-G-as can be used. For the heat treatment at T _u , such conditions are chosen that either bulk precipitates and secondary defects develop in sufficient density (criterion: gate efficiency) or precipitate nuclei are induced in sufficient density.

"OOOS

which are only developed during subsequent high-temperature steps at temperatures T ^> T _u to corresponding precipitates and secondary defects, depending on the device technology or «to be realized Getterungseffekt * '

The depletion layer on the surface due to outdiffusion during the heat treatment at T effects homogenization of the near-surface regions in terms of impurity concentration and, in particular, prevents the formation of precipitate nuclei in these critical regions (oxygen concentration insufficient) during the heat treatment at G? , d. h _o the formation of the oxygen-coupled precipitates is shifted to deeper disc areas. This is in addition to a reduced excitation already existing - growth-induced and treatment-induced (cycle 0) - near-surface displacement sources an advantage of Yfärmebehandlung invention, compared to a corresponding heat treatment with reverse temperature (T temporally before T _Q ).

It has been found that a heat treatment according to the invention - compared to reverse temperature control / 3 / - leads to significantly lower Soheibenverwerfung, on the other hand at lower microdefect density in the volume causes a comparable gettering effect (Volumengetterung). At the same time, the defect-depleted near-surface region is substantially lower than in the case of reverse temperature control and comparable periods of heat treatment, ie. H. structurally and chemically nearly perfect substrate surface areas as electrically active zones of electronic components are created in economically favorable times «

Embodiment:

Starting from dislocation-free Czochralski silicon disks having a starting concentration of interstitial oxygen of Ps-8 β 10 cm and a growth-related microdefect (substantially precipitate) density of about 10 cm, variants of the heat treatment according to the invention are described,

, - 5- 22 63 89

(1) Heat treatment of the disks at. T _Q = 1000 ^° C

(30 minutes under H ₂ ) and at T = 850 ⁰ C (300 minutes under Ar) leads to significant Ausdiffusion of oxygen and to the formation of precipitate nuclei, which during subsequent heat treatment at T ^ = 1050 ⁰ C (180 minutes under a humid O ₂ ) develop extensive Yolumendefekte, starting at a depth of some / Um below the substrate surface and some / To deeper in.eine

9 Ly passing saturation concentration of about 10 om.

(2) Heat treatment of the disks at T _Q = 1000 ^° C

(20 minutes under 1 " ₂ ZO ₂ ZHC1 mixture, then 170 minutes under N ₂ Z0 ₂ ~ mixture) and at T _u = 850 ⁰ C (300 minutes under 1T ₂ ZO ₂ mixture) leads to a stronger outdiffusion of oxygen as after corresponding heat treatments according to embodiment (1) and for the formation of extensive volume defects which occur at a depth of a few / μm below the surface of the substrate and some / μm deeper into a saturation concentration in the

'Q -3

Order of 10 om pass.

(3) A heat treatment at T _Q = 1100 ⁰ C (2Q minutes under O ₂ ZHC1 mixture, then 200 minutes under humid O ₂ ) and then at T _u = 900 ⁰ C (180 minutes under dry O ₂ ) on this Si -Substraten leads to an even greater outdiffusion of oxygen than after corresponding heat treatments according to embodiment (1) and also to the formation of extensive volume defects in the embodiment described in the embodiment (2) »

Literature:.

ZV Tan, T _e Y, £ Gardner j EE "; Tice, W * K. , Apple Phys * Lett. 30, 175 (1977)

Z2 / Rozgonyi, G "A _e ; Pearce, CW «

Appl. Phys. Lett. 32, 747 (1978)

/ 3 / Yamamoto, K .; Kishino _? S "; Matsushita, Y ₀ ; Iizuka _? T "Appl Phys _{e e o} Lett 36, 195 (1980)

- 6 · 2 26383

./4/ Roiagonyi, G _e A _e ; Deysher, Β · Ρ ·; Pearce, CW. _E electropohem. Soo. 122, ¹ ^ IO (1976)

/ 5 / -Hu, SA

J _e Vao. Sol. Technol. U, 17 (1977)

/ 6 / Moerschelj K _e G- _e j Pearoe _? CT. \ T _e j Reusser, R 'e _e Semioonde silicone _1977? S ₉ 170 - 181 Publisher Huff, H _e R »; Slrtl · E ₀

/ 7 / Leroy, B * j Plougonven, C ₉ J _e Eleotroohem. Soo. i2 £, 961 (1980)

Claims (1)

Invention claim: 1 _β Terfahren for increasing the component yield on Si ·%. 17 -3 substrate disks with an oxygen content S 6. 10 centimeters , characterized in that the silicon soils are subjected to such a heat treatment that a first heat treatment in the temperature range 900 ^ T _Q ύ 1300 ⁰ C and a second in the range 600 <T _u £ 900 ⁰ C are performed, according to the applied device technology and the Si substrate material used optionally connect further heat treatments at T ' P ¹ T to further improve the disk properties according to the invention, and / or add the heat treatments. T _Q , T and optionally T 'from a few minutes to several hours under various media, e.g. B ₀ oxidizing, reducing or inert with such additives vd.e HCl-G-as, media mixtures or in vacuo and the heat treatments at T ₀ , T and optionally T ^ either sequentially or separately before and / or between typical process steps of the components Technology, such as oxidation, diffusion and epitaxy, or using such typical process steps of the device technology or partly separately, partly using typical process steps of the device element technology. Z _{9 The} method according to item 1, characterized in that the heat treatments at T _Qj T, optionally T ' _{9 are carried out} according to different temperature-time Fünktionen, z _e B. with one or more breakpoints or with monotonous i tion of the temperature, optionally under Linking the typical temperature ranges for the different heat treatments ₆