CN117790351A - Epitaxial growth method and device - Google Patents

Abstract

The invention provides an epitaxial growth method and device, and belongs to the technical field of semiconductor manufacturing. An epitaxial growth method comprising: feeding a wafer into an epitaxial reaction chamber, and growing an epitaxial layer on the wafer; acquiring resistivity information of the epitaxial layer, wherein the epitaxial layer is divided into a plurality of areas, and the resistivity information comprises the resistivity of each area of the epitaxial layer; judging whether the resistivity information meets the preset resistivity uniformity requirement, and if not, adjusting the position of the heating module of the epitaxial reaction chamber until the resistivity information meets the preset resistivity uniformity requirement. According to the technical scheme, the temperature field of the epitaxial reaction chamber can be adjusted, and the resistivity uniformity of the epitaxial wafer is improved.

Description

Epitaxial growth method and device

Technical Field

The present invention relates to the field of semiconductor manufacturing technology, and in particular, to an epitaxial growth method and apparatus.

Background

The growth of a single crystal thin film on a single crystal polished wafer is called an epitaxial wafer, and compared with the polished wafer, the epitaxial wafer has the characteristics of less surface defects, excellent crystallinity and controllable resistivity, and is widely used in highly integrated circuit (integrated circuit, IC) elements and Metal-Oxide-Semiconductor (MOS) processes.

Generally, a single crystal silicon wafer (wafer) is epitaxially grown by chemical vapor deposition, the single crystal silicon wafer is first transferred to a Susceptor (Susceptor) for carrying the wafer in an epitaxial reaction chamber, then the epitaxial reaction chamber is heated, and a cleaning gas (H) is introduced into the epitaxial reaction chamber after a predetermined temperature is reached ₂ ) And removing natural oxides on the surface of the monocrystalline silicon wafer, and then feeding silicon source gas to continuously and uniformly grow a silicon epitaxial layer on the front surface of the monocrystalline silicon wafer.

The resistivity, also referred to as resistivity or specific resistance, is an electrical parameter that represents the ability of a material to resist directional movement of charged particles in an electric field, the relationship between resistivity and resistance of a material being: ρ=rs/L, where ρ is the resistivity, S is the cross-sectional area, R is the resistance value, and L is the conductive region length. The resistivity is an important parameter for measuring the electrical performance of the epitaxial wafer, is inversely proportional to the conductivity, and the size of the resistivity is mainly dependent on the temperature, the pressure and the doping concentration.

In the prior art, when epitaxial growth is carried out, the temperature field of the epitaxial reaction chamber is unstable and is not easy to adjust, so that the resistivity of the epitaxial wafer is uneven, and the product yield of the epitaxial wafer is affected.

Disclosure of Invention

In order to solve the technical problems, the invention provides an epitaxial growth method and device, which can adjust the temperature field of an epitaxial reaction chamber and improve the resistivity uniformity of an epitaxial wafer.

In order to achieve the above purpose, the technical scheme adopted by the embodiment of the invention is as follows:

an epitaxial growth method comprising:

feeding a wafer into an epitaxial reaction chamber, and growing an epitaxial layer on the wafer;

acquiring resistivity information of the epitaxial layer, wherein the epitaxial layer is divided into a plurality of areas, and the resistivity information comprises the resistivity of each area of the epitaxial layer;

judging whether the resistivity information meets the preset resistivity uniformity requirement or not;

if the resistivity information does not meet the preset resistivity uniformity requirement, the position of the heating module of the epitaxial reaction chamber is adjusted until the resistivity information meets the preset resistivity uniformity requirement.

In some embodiments, the predetermined resistivity uniformity requirement is that the resistivity of each of the regions does not differ from the target resistivity by more than a predetermined threshold.

In some embodiments, the heating module comprises an upper heating module located above a susceptor in the epitaxial reaction chamber and a lower heating module located below the susceptor in the epitaxial reaction chamber, the upper heating module comprising at least one turn of heating bulbs disposed about the susceptor, the lower heating module comprising at least one turn of heating bulbs disposed about the susceptor, the adjusting the position of the heating module of the epitaxial reaction chamber comprising:

when the resistivity of a target area of the epitaxial layer is larger than the target resistivity and the difference value between the resistivity and the target resistivity is larger than a preset threshold value, controlling the heating bulb corresponding to the target area to rotate in a direction approaching to the base, so that the heating bulb moves from a first position to a second position, wherein an angle formed by an axis of the heating bulb and the horizontal direction is a first angle when the heating bulb is at the first position, an angle formed by the axis of the heating bulb and the horizontal direction is a second angle when the heating bulb is at the second position, and an angle difference between the first angle and the second angle is a first preset angle;

when the resistivity of the target area of the epitaxial layer is smaller than the target resistivity and the difference value between the resistivity and the target resistivity is larger than a preset threshold value, the heating bulb corresponding to the target area is controlled to rotate in a direction away from the base, so that the heating bulb moves from a third position to a fourth position, an angle formed by the axis of the heating bulb and the horizontal direction in the third position is a third angle, an angle formed by the axis of the heating bulb and the horizontal direction in the fourth position is a fourth angle, and an angle difference between the third angle and the fourth angle is a second preset angle.

In some embodiments, the heating bulb includes a lamp holder support and a bulb body fixed on the lamp holder support, the lamp holder support includes a rotary lamp holder body and a rotation adjusting mechanism below the rotary lamp holder body, the bulb body is fixed on the lamp holder support through the rotary lamp holder body, the rotary lamp holder body is driven to rotate through the rotation adjusting mechanism so as to control the bulb body to rotate on a plane perpendicular to a horizontal direction, and the controlling the heating bulb to rotate includes:

and the angle formed by the bulb body and the horizontal direction is adjusted through the rotation adjusting mechanism.

In some embodiments, the first preset angle is 3-5 ° and the second preset angle is 3-5 °.

The embodiment of the invention also provides an epitaxial growth device, which comprises:

the growth module is used for sending the wafer into the epitaxial reaction chamber and growing an epitaxial layer on the wafer;

the information acquisition module is used for acquiring resistivity information of the epitaxial layer, wherein the epitaxial layer is divided into a plurality of areas, and the resistivity information comprises the resistivity of each area of the epitaxial layer;

the judging module is used for judging whether the resistivity information meets the preset resistivity uniformity requirement;

and the adjusting module is used for adjusting the position of the heating module of the epitaxial reaction chamber if the resistivity information does not meet the preset resistivity uniformity requirement until the resistivity information meets the preset resistivity uniformity requirement.

In some embodiments, the predetermined resistivity uniformity requirement is that the resistivity of each of the regions does not differ from the target resistivity by more than a predetermined threshold.

In some embodiments, the heating module comprises an upper heating module located above a susceptor in an epitaxial reaction chamber and a lower heating module located below a susceptor in the epitaxial reaction chamber, the upper heating module comprising at least one turn of heating bulbs disposed about the susceptor, the lower heating module comprising at least one turn of heating bulbs disposed about the susceptor,

the adjusting module is specifically configured to control the heating bulb corresponding to the target area to rotate in a direction approaching the base when the resistivity of the target area of the epitaxial layer is greater than a target resistivity and a difference value between the target resistivity and the target resistivity is greater than a preset threshold, so that the heating bulb moves from a first position to a second position, an angle formed by an axis of the heating bulb and a horizontal direction is a first angle in the first position, an angle formed by the axis of the heating bulb and the horizontal direction is a second angle in the second position, and an angle difference between the first angle and the second angle is a first preset angle;

when the resistivity of the target area of the epitaxial layer is smaller than the target resistivity and the difference value between the resistivity and the target resistivity is larger than a preset threshold value, the heating bulb corresponding to the target area is controlled to rotate in a direction away from the base, so that the heating bulb moves from a third position to a fourth position, an angle formed by the axis of the heating bulb and the horizontal direction in the third position is a third angle, an angle formed by the axis of the heating bulb and the horizontal direction in the fourth position is a fourth angle, and an angle difference between the third angle and the fourth angle is a second preset angle.

In some embodiments, the heating bulb comprises a bulb holder and a bulb body fixed on the bulb holder, the bulb holder comprises a rotary lamp holder body and a rotary adjusting mechanism below the rotary lamp holder body, the bulb body is fixed on the bulb holder through the rotary lamp holder body, the rotary lamp holder body is driven to rotate through the rotary adjusting mechanism so as to control the bulb body to rotate on a plane vertical to the horizontal direction,

the adjusting module is specifically used for adjusting the angle formed by the bulb body and the horizontal direction through the rotary adjusting mechanism.

In some embodiments, the first preset angle is 3-5 ° and the second preset angle is 3-5 °.

The beneficial effects of the invention are as follows:

in this embodiment, after an epitaxial layer is epitaxially grown on a wafer, resistivity information of the epitaxial layer is obtained, and when the resistivity information does not meet a preset resistivity uniformity requirement, the position of a heating module of an epitaxial reaction chamber is adjusted, so that a temperature field of the epitaxial reaction chamber is adjusted.

Drawings

FIG. 1 shows a schematic structural view of an epitaxial reaction chamber;

FIG. 2 is a flow chart of an epitaxial growth method according to an embodiment of the present invention;

FIG. 3 shows a schematic representation of epitaxial layer resistivity;

FIG. 4 is a graph showing the uniformity of resistivity of an epitaxial layer of the prior art;

FIG. 5 is a graph showing the resistivity uniformity of epitaxial layers prepared in accordance with an embodiment of the present invention;

fig. 6 is a block diagram showing the structure of an epitaxial growth apparatus according to an embodiment of the present invention.

Reference numerals

01. Upper thermometer

02. Upper heating module

03. Lower heating module

04. Base ring

05. Nozzle

06. Upper coil

07. Lower temperature measuring instrument

08. Downdome

09 lower coil

10. Exhaust cover

11. Upper dome

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. It will be apparent that the described embodiments are some, but not all, embodiments of the invention. All other embodiments, which are obtained by a person skilled in the art based on the described embodiments of the invention, fall within the scope of protection of the invention.

Fig. 1 shows a schematic structural diagram of an epitaxial reaction chamber, and as shown in fig. 1, the epitaxial reaction chamber comprises an upper thermometer 01, an upper heating module 02, a lower heating module 03, a base ring 04, a nozzle 05, an upper coil 06, a lower thermometer 07, a lower dome 08, a lower coil 09, an exhaust cover 10, an upper dome 11 and other components.

In the related art, a heating module of an epitaxial reaction chamber is generally heated by heating bulbs, as shown in fig. 1, in the epitaxial reaction chamber, a plurality of groups of heating bulbs are respectively fixed on the upper side and the lower side of a base for heating a wafer, and the heating mode has the advantages of simple operation and high heating speed, but also has the problems of fixed temperature field and difficult control of the surface temperature of the wafer. These problems can result in the resistivity and thickness uniformity of the grown epitaxial layers being affected, which is detrimental to the production of high quality epitaxial wafers.

In order to solve the technical problems, the invention provides an epitaxial growth method and device, which can adjust the temperature field of an epitaxial reaction chamber and improve the resistivity uniformity of an epitaxial wafer.

An embodiment of the present invention provides an epitaxial growth method, as shown in fig. 2, including:

step 101: feeding a wafer into an epitaxial reaction chamber, and growing an epitaxial layer on the wafer;

in this embodiment, the heating module of the epitaxial reaction chamber includes an upper heating module located above the susceptor in the epitaxial reaction chamber and a lower heating module located below the susceptor in the epitaxial reaction chamber, the upper heating module includes at least one circle of heating bulbs surrounding the susceptor, and the lower heating module includes at least one circle of heating bulbs surrounding the susceptor. When epitaxial growth is carried out, the angle of the heating bulb can be fixed, and the heating bulb is placed at a designated position of the heating module.

Step 102: acquiring resistivity information of the epitaxial layer, wherein the epitaxial layer is divided into a plurality of areas, and the resistivity information comprises the resistivity of each area of the epitaxial layer;

and after the epitaxial growth is finished, the resistivity information of the epitaxial layer can be obtained through testing. Fig. 3 shows a schematic diagram of the resistivity of an epitaxial layer, the epitaxial layer is divided into a plurality of regions, in fig. 3, a small square represents a region, and the shade of each region represents the resistivity of the region. The higher the temperature of the region during epitaxial growth, the more dopant is doped and the lower the resistivity, so the temperature field can be reacted by the resistivity profile.

Step 103: judging whether the resistivity information meets the preset resistivity uniformity requirement or not;

in some embodiments, the predetermined resistivity uniformity requirement is that the resistivity of each of the regions does not differ from the target resistivity by more than a predetermined threshold. The value of the preset threshold value can be set in advance according to the requirement, and when the resistivity difference value between the resistivity of each region and the target resistivity does not exceed the preset threshold value, the epitaxial layer has good resistivity uniformity.

Step 104: if the resistivity information does not meet the preset resistivity uniformity requirement, the position of the heating module of the epitaxial reaction chamber is adjusted until the resistivity information meets the preset resistivity uniformity requirement.

In this embodiment, the angle between the heating bulb and the horizontal direction may be adjusted. Specifically, the angle formed by all or part of the heating bulbs in the upper heating module and the horizontal direction can be adjusted, the angle formed by all or part of the heating bulbs in the lower heating module and the horizontal direction can be also adjusted, the adjusted angle can be determined by the resistivity of the epitaxial layer region corresponding to the heating bulbs, and the heat radiated to the epitaxial layer by the heating bulbs can be changed by adjusting the angle formed by the heating bulbs and the horizontal direction, so that the temperature field distribution in the epitaxial reaction chamber is changed.

In this embodiment, after an epitaxial layer is epitaxially grown on a wafer, resistivity information of the epitaxial layer is obtained, and when the resistivity information does not meet a preset resistivity uniformity requirement, the position of a heating module of an epitaxial reaction chamber is adjusted, so that a temperature field of the epitaxial reaction chamber is adjusted.

In some embodiments, the heating bulb comprises a lamp holder support and a bulb body fixed on the lamp holder support, the lamp holder support comprises a rotary lamp holder body and a rotary adjusting mechanism below the rotary lamp holder body, the bulb body is fixed on the lamp holder support through the rotary lamp holder body, the rotary lamp holder body is driven to rotate through the rotary adjusting mechanism, the bulb body can be controlled to rotate on a plane perpendicular to the horizontal direction, and the angle formed by the bulb body and the horizontal direction can be adjusted through the rotary adjusting mechanism.

In this embodiment, the heating bulbs are disposed around the susceptor, each heating bulb may correspond to one or more regions of the epitaxial layer, most (greater than 80%) or all of the heat radiated by the heating bulb may reach the corresponding region, and the angle of the heating bulb may be adjusted according to the resistivity of the corresponding region. In some embodiments, the adjusting the angle of the heating bulb to the horizontal comprises:

when the resistivity of a target area of the epitaxial layer is larger than the target resistivity and the difference value between the resistivity and the target resistivity is larger than a preset threshold value, controlling the heating bulb corresponding to the target area to rotate in a direction approaching to the base, so that the heating bulb moves from a first position to a second position, wherein an angle formed by an axis of the heating bulb and the horizontal direction is a first angle when the heating bulb is at the first position, an angle formed by the axis of the heating bulb and the horizontal direction is a second angle when the heating bulb is at the second position, and an angle difference between the first angle and the second angle is a first preset angle;

when the resistivity of the target area of the epitaxial layer is smaller than the target resistivity and the difference value between the resistivity and the target resistivity is larger than a preset threshold value, the heating bulb corresponding to the target area is controlled to rotate in a direction away from the base, so that the heating bulb moves from a third position to a fourth position, an angle formed by the axis of the heating bulb and the horizontal direction in the third position is a third angle, an angle formed by the axis of the heating bulb and the horizontal direction in the fourth position is a fourth angle, and an angle difference between the third angle and the fourth angle is a second preset angle.

The higher the temperature of the epitaxial layer region is, the lower the resistivity is, so when the resistivity of the target region of the epitaxial layer is smaller than the target resistivity and the difference value between the target resistivity and the target resistivity is larger than a preset threshold value, the temperature of the target region needs to be reduced, and therefore the heating bulb corresponding to the target region is controlled to rotate a preset angle in a direction away from the base, so that the heat radiated to the corresponding epitaxial layer region by the heating bulb can be reduced, and the temperature of the epitaxial layer region corresponding to the heating bulb is reduced; when the resistivity of the target area of the epitaxial layer is larger than the target resistivity and the difference between the target resistivity and the target resistivity is larger than a preset threshold, the temperature of the target area needs to be increased, so that the heating bulb corresponding to the target area is controlled to rotate by a preset angle towards the direction close to the base, the heat radiated to the corresponding epitaxial layer area by the heating bulb can be increased, and the temperature of the epitaxial layer area corresponding to the heating bulb is increased.

In this embodiment, in order to avoid excessive fluctuation of the room temperature field of the epitaxial reaction chamber and influence the yield of the product, the angle formed by the heating bulb and the horizontal direction is adjusted according to the first preset angle and the second preset angle each time, that is, in two adjacent epitaxial growth, the difference between the angles formed by the heating bulb and the horizontal direction does not exceed the first preset angle or the second preset angle. The preset angle of each adjustment of the heating bulb may be empirically set, the first preset angle may be 3-5 °, and the second preset angle may be 3-5 °.

Specifically, after finishing the Mth epitaxial growth, acquiring resistivity information of the wafer epitaxial layer, and if the resistivity of the wafer epitaxial layer does not meet the preset resistivity uniformity requirement, adjusting the angle of the heating bulb according to the resistivity information of the epitaxial layer according to the embodiment; and after finishing the M+1th epitaxial growth, acquiring the resistivity information of the wafer epitaxial layer again, and if the resistivity of the wafer epitaxial layer does not meet the preset resistivity uniformity requirement, adjusting the angle of the heating bulb according to the resistivity information of the epitaxial layer according to the embodiment. And the like until the resistivity of the wafer epitaxial layer meets the preset resistivity uniformity requirement, wherein M is a positive integer. In addition, if the angle of the axis of the heating bulb with respect to the horizontal direction is greater than a set angle threshold value, such as 5 °, after the angle of the heating bulb is adjusted, the adjustment of the angle of the heating bulb is stopped.

FIG. 4 is a schematic diagram showing the uniformity of the resistivity of the conventional epitaxial layer, wherein the abscissa is the coordinates of different regions of the epitaxial layer, and the ordinate is the resistivity index of the epitaxial layer, and it can be seen that the uniformity of the resistivity of the conventional epitaxial layer is poor; fig. 5 is a schematic diagram showing the uniformity of resistivity of an epitaxial layer prepared by the embodiment of the present invention, wherein the abscissa is the coordinates of different regions of the epitaxial layer, and the ordinate is the resistivity index of the epitaxial layer, and it can be seen that the uniformity of resistivity of the epitaxial layer prepared by the embodiment of the present invention is improved.

In the prior art, the resistivity uniformity of the epitaxial layer is typically 3%. As shown in fig. 1, the upper heating module 02 includes heating bulbs a and b, and the lower heating module 03 includes a row of heating bulbs c and a row of heating bulbs d. In a specific example, rotating heating bulb a and heating bulb c up to 5 ° in the direction shown in the figure can increase the resistivity uniformity of the epitaxial layer to 2.6%; rotating heating bulb b and heating bulb d 5 ° downward in the direction shown in the figure can increase the resistivity uniformity of the epitaxial layer to 2.5%; the heating bulb a is rotated by 5 degrees upwards in the direction shown in the figure, and the heating bulb b is rotated by 5 degrees downwards in the direction shown in the figure, so that the resistivity uniformity of the epitaxial layer can be improved to 2.7%; the resistivity uniformity of the epitaxial layer can be improved to 2.6% by rotating the heating bulb c 5 ° upward in the direction shown in the figure and rotating the heating bulb d 5 ° downward in the direction shown in the figure. Through the technical scheme of the embodiment, the resistivity uniformity of the epitaxial layer can be effectively improved.

In this embodiment, the rotation angle of the heating bulb may be measured by the protractor, specifically, the angle between the reflecting plate and the bulb wall of the heating bulb in the epitaxial reaction chamber may be measured, and the rotation angle of the heating bulb may be measured by the angle between the reflecting plate and the bulb wall of the heating bulb.

According to the embodiment, the temperature field of the epitaxial reaction chamber can be effectively adjusted by changing the angle of the heating bulb, so that the temperature of the wafer is more uniform, the resistivity uniformity of the epitaxial layer is further improved, and after the resistivity uniformity of the epitaxial layer is improved, the thickness uniformity of the epitaxial layer is correspondingly improved; according to the embodiment, the resistivity of the wafer epitaxial layer is monitored to feed back the temperature field in real time, so that the production process can be controlled more accurately, and the production efficiency and quality are improved; the technical scheme of the embodiment has strong practicability and can be widely applied to the production of various wafer APCVD (atmospheric pressure chemical vapor deposition) epitaxial processes.

The embodiment of the invention also provides an epitaxial growth device, as shown in fig. 6, which comprises:

a growth module 21 for feeding a wafer into the epitaxial reaction chamber, on which an epitaxial layer is grown;

in this embodiment, the heating module of the epitaxial reaction chamber includes an upper heating module located above the susceptor in the epitaxial reaction chamber and a lower heating module located below the susceptor in the epitaxial reaction chamber, the upper heating module includes at least one circle of heating bulbs surrounding the susceptor, and the lower heating module includes at least one circle of heating bulbs surrounding the susceptor. When epitaxial growth is carried out, the angle of the heating bulb can be fixed, and the heating bulb is placed at a designated position of the heating module.

An information obtaining module 22, configured to obtain resistivity information of the epitaxial layer, where the epitaxial layer is divided into a plurality of regions, and the resistivity information includes resistivity of each region of the epitaxial layer;

and after the epitaxial growth is finished, the resistivity information of the epitaxial layer can be obtained through testing. Fig. 3 shows a schematic diagram of the resistivity of an epitaxial layer, the epitaxial layer is divided into a plurality of regions, in fig. 3, a small square represents a region, and the shade of each region represents the resistivity of the region. The higher the temperature of the region during epitaxial growth, the more dopant is doped and the lower the resistivity, so the temperature field can be reacted by the resistivity profile.

A judging module 23, configured to judge whether the resistivity information meets a preset resistivity uniformity requirement;

in some embodiments, the predetermined resistivity uniformity requirement is that the resistivity of each of the regions does not differ from the target resistivity by more than a predetermined threshold. The value of the preset threshold value can be set in advance according to the requirement, and when the resistivity difference value between the resistivity of each region and the target resistivity does not exceed the preset threshold value, the epitaxial layer has good resistivity uniformity.

And the adjusting module 24 is configured to adjust the position of the heating module of the epitaxial reaction chamber until the resistivity information meets the preset resistivity uniformity requirement if the resistivity information does not meet the preset resistivity uniformity requirement.

In this embodiment, the adjustment module 24 may adjust the angle between the heating bulb and the horizontal direction. Specifically, the adjusting module 24 may adjust an angle formed by all or part of the heating bulbs in the upper heating module and the horizontal direction, or may adjust an angle formed by all or part of the heating bulbs in the lower heating module and the horizontal direction, where the adjusted angle may be determined by a resistivity of an epitaxial layer region corresponding to the heating bulbs, and by adjusting an angle formed by the heating bulbs and the horizontal direction, an amount of heat radiated to the epitaxial layer by the heating bulbs may be changed, and a temperature field distribution in the epitaxial reaction chamber may be changed.

In this embodiment, after an epitaxial layer is epitaxially grown on a wafer, resistivity information of the epitaxial layer is obtained, and when the resistivity information does not meet a preset resistivity uniformity requirement, the position of a heating module of an epitaxial reaction chamber is adjusted, so that a temperature field of the epitaxial reaction chamber is adjusted.

In some embodiments, the heating bulb includes a lamp holder support and a bulb body fixed on the lamp holder support, the lamp holder support includes a rotary lamp holder body and a rotation adjusting mechanism below the rotary lamp holder body, the bulb body is fixed on the lamp holder support through the rotary lamp holder body, the rotary lamp holder body is driven to rotate through the rotation adjusting mechanism, the bulb body can be controlled to rotate on a plane perpendicular to a horizontal direction, and the adjusting module 24 can adjust an angle formed by the bulb body and the horizontal direction through the rotation adjusting mechanism.

In this embodiment, the heating bulbs are disposed around the susceptor, each heating bulb may correspond to one or more regions of the epitaxial layer, most (greater than 80%) or all of the heat radiated by the heating bulb may reach the corresponding region, and the angle of the heating bulb may be adjusted according to the resistivity of the corresponding region.

The adjustment module 24 is specifically configured to control the heating bulb corresponding to the target area to rotate in a direction approaching the base when the resistivity of the target area of the epitaxial layer is greater than a target resistivity and a difference between the target resistivity and the target resistivity is greater than a preset threshold, so that the heating bulb moves from a first position to a second position, an angle formed by an axis of the heating bulb and a horizontal direction is a first angle in the first position, an angle formed by an axis of the heating bulb and a horizontal direction is a second angle in the second position, and an angle difference between the first angle and the second angle is a first preset angle;

when the resistivity of the target area of the epitaxial layer is smaller than the target resistivity and the difference value between the resistivity and the target resistivity is larger than a preset threshold value, the heating bulb corresponding to the target area is controlled to rotate in a direction away from the base, so that the heating bulb moves from a third position to a fourth position, an angle formed by the axis of the heating bulb and the horizontal direction in the third position is a third angle, an angle formed by the axis of the heating bulb and the horizontal direction in the fourth position is a fourth angle, and an angle difference between the third angle and the fourth angle is a second preset angle.

The higher the temperature of the epitaxial layer region is, the lower the resistivity is, so when the resistivity of the target region of the epitaxial layer is smaller than the target resistivity and the difference value between the target resistivity and the target resistivity is larger than a preset threshold value, the temperature of the target region needs to be reduced, and therefore the heating bulb corresponding to the target region is controlled to rotate a preset angle in a direction away from the base, so that the heat radiated to the corresponding epitaxial layer region by the heating bulb can be reduced, and the temperature of the epitaxial layer region corresponding to the heating bulb is reduced; when the resistivity of the target area of the epitaxial layer is larger than the target resistivity and the difference between the target resistivity and the target resistivity is larger than a preset threshold, the temperature of the target area needs to be increased, so that the heating bulb corresponding to the target area is controlled to rotate by a preset angle towards the direction close to the base, the heat radiated to the corresponding epitaxial layer area by the heating bulb can be increased, and the temperature of the epitaxial layer area corresponding to the heating bulb is increased.

In this embodiment, in order to avoid excessive fluctuation of the room temperature field of the epitaxial reaction chamber and influence the yield of the product, the adjustment module 24 adjusts the angle formed by the heating bulb and the horizontal direction according to the first preset angle and the second preset angle each time, that is, the difference between the angles formed by the heating bulb and the horizontal direction in two adjacent epitaxial growth does not exceed the first preset angle or the second preset angle. The preset angle of each adjustment of the heating bulb may be empirically set, the first preset angle may be 3-5 °, and the second preset angle may be 3-5 °.

Specifically, after finishing the mth epitaxial growth, obtaining the resistivity information of the wafer epitaxial layer, and if the resistivity of the wafer epitaxial layer does not meet the preset resistivity uniformity requirement, adjusting the angle of the heating bulb by the adjusting module 24 according to the resistivity information of the epitaxial layer in the above embodiment; after the m+1th epitaxial growth is completed, the resistivity information of the wafer epitaxial layer is obtained again, and if the resistivity of the wafer epitaxial layer does not meet the preset resistivity uniformity requirement, the adjustment module 24 adjusts the angle of the heating bulb according to the resistivity information of the epitaxial layer again according to the above embodiment. And the like until the resistivity of the wafer epitaxial layer meets the preset resistivity uniformity requirement, wherein M is a positive integer. In addition, if the angle of the axis of the heating bulb with respect to the horizontal direction is greater than a set angle threshold value, such as 5 °, after the angle of the heating bulb is adjusted, the adjustment of the angle of the heating bulb is stopped.

In this specification, all embodiments are described in a progressive manner, and identical and similar parts of the embodiments are all referred to each other, and each embodiment is mainly described in a different way from other embodiments. In particular, for the embodiments, since they are substantially similar to the product embodiments, the description is relatively simple, and the relevant points are found in the section of the product embodiments.

Unless defined otherwise, technical or scientific terms used in this disclosure should be given the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure belongs. The terms "first," "second," and the like, as used in this disclosure, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that elements or items preceding the word are included in the element or item listed after the word and equivalents thereof, but does not exclude other elements or items. The terms "connected" or "connected," and the like, are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", etc. are used merely to indicate relative positional relationships, which may also be changed when the absolute position of the object to be described is changed.

It will be understood that when an element such as a layer, film, region or substrate is referred to as being "on" or "under" another element, it can be "directly on" or "under" the other element or intervening elements may be present.

In the description of the above embodiments, particular features, structures, materials, or characteristics may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing is merely specific embodiments of the disclosure, but the protection scope of the disclosure is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the disclosure, and it is intended to cover the scope of the disclosure. Therefore, the protection scope of the present disclosure shall be subject to the protection scope of the claims.

Claims (10)

1. A method of epitaxial growth comprising:

feeding a wafer into an epitaxial reaction chamber, and growing an epitaxial layer on the wafer;

acquiring resistivity information of the epitaxial layer, wherein the epitaxial layer is divided into a plurality of areas, and the resistivity information comprises the resistivity of each area of the epitaxial layer;

judging whether the resistivity information meets the preset resistivity uniformity requirement or not;

if the resistivity information does not meet the preset resistivity uniformity requirement, the position of the heating module of the epitaxial reaction chamber is adjusted until the resistivity information meets the preset resistivity uniformity requirement.

2. The epitaxial growth method of claim 1, wherein the predetermined resistivity uniformity requirement is that the resistivity of each of the regions does not differ from the target resistivity by more than a predetermined threshold.

3. The epitaxial growth method of claim 2, wherein the heating module comprises an upper heating module located above a susceptor in an epitaxial reaction chamber and a lower heating module located below the susceptor in the epitaxial reaction chamber, the upper heating module comprising at least one turn of heating bulbs disposed around the susceptor, the lower heating module comprising at least one turn of heating bulbs disposed around the susceptor, the adjusting the position of the heating module of the epitaxial reaction chamber comprising:

when the resistivity of a target area of the epitaxial layer is larger than the target resistivity and the difference value between the resistivity and the target resistivity is larger than a preset threshold value, controlling the heating bulb corresponding to the target area to rotate in a direction approaching to the base, so that the heating bulb moves from a first position to a second position, wherein an angle formed by an axis of the heating bulb and the horizontal direction is a first angle when the heating bulb is at the first position, an angle formed by the axis of the heating bulb and the horizontal direction is a second angle when the heating bulb is at the second position, and an angle difference between the first angle and the second angle is a first preset angle;

when the resistivity of the target area of the epitaxial layer is smaller than the target resistivity and the difference value between the resistivity and the target resistivity is larger than a preset threshold value, the heating bulb corresponding to the target area is controlled to rotate in a direction away from the base, so that the heating bulb moves from a third position to a fourth position, an angle formed by the axis of the heating bulb and the horizontal direction in the third position is a third angle, an angle formed by the axis of the heating bulb and the horizontal direction in the fourth position is a fourth angle, and an angle difference between the third angle and the fourth angle is a second preset angle.

4. The epitaxial growth method according to claim 3, wherein the heating bulb comprises a bulb holder and a bulb body fixed on the bulb holder, the bulb holder comprises a rotary lamp holder body and a rotary adjusting mechanism below the rotary lamp holder body, the bulb body is fixed on the bulb holder through the rotary lamp holder body, the rotary lamp holder body is driven to rotate through the rotary adjusting mechanism so as to control the bulb body to rotate on a plane perpendicular to a horizontal direction, and the controlling the heating bulb to rotate comprises:

and the angle formed by the bulb body and the horizontal direction is adjusted through the rotation adjusting mechanism.

5. An epitaxial growth method according to claim 3, characterized in that the first preset angle is 3-5 ° and the second preset angle is 3-5 °.

6. An epitaxial growth apparatus, comprising:

the growth module is used for sending the wafer into the epitaxial reaction chamber and growing an epitaxial layer on the wafer;

the information acquisition module is used for acquiring resistivity information of the epitaxial layer, wherein the epitaxial layer is divided into a plurality of areas, and the resistivity information comprises the resistivity of each area of the epitaxial layer;

the judging module is used for judging whether the resistivity information meets the preset resistivity uniformity requirement;

and the adjusting module is used for adjusting the position of the heating module of the epitaxial reaction chamber if the resistivity information does not meet the preset resistivity uniformity requirement until the resistivity information meets the preset resistivity uniformity requirement.

7. The epitaxial growth apparatus of claim 6, wherein the predetermined resistivity uniformity requirement is that the resistivity of each of the regions does not differ from the target resistivity by more than a predetermined threshold.

8. The epitaxial growth apparatus of claim 7 wherein the heating module comprises an upper heating module located above a susceptor in an epitaxial reaction chamber and a lower heating module located below a susceptor in the epitaxial reaction chamber, the upper heating module comprising at least one turn of heating bulbs disposed about the susceptor, the lower heating module comprising at least one turn of heating bulbs disposed about the susceptor,

the adjusting module is specifically configured to control the heating bulb corresponding to the target area to rotate in a direction approaching the base when the resistivity of the target area of the epitaxial layer is greater than a target resistivity and a difference value between the target resistivity and the target resistivity is greater than a preset threshold, so that the heating bulb moves from a first position to a second position, an angle formed by an axis of the heating bulb and a horizontal direction is a first angle in the first position, an angle formed by the axis of the heating bulb and the horizontal direction is a second angle in the second position, and an angle difference between the first angle and the second angle is a first preset angle;

when the resistivity of the target area of the epitaxial layer is smaller than the target resistivity and the difference value between the resistivity and the target resistivity is larger than a preset threshold value, the heating bulb corresponding to the target area is controlled to rotate in a direction away from the base, so that the heating bulb moves from a third position to a fourth position, an angle formed by the axis of the heating bulb and the horizontal direction in the third position is a third angle, an angle formed by the axis of the heating bulb and the horizontal direction in the fourth position is a fourth angle, and an angle difference between the third angle and the fourth angle is a second preset angle.

9. The epitaxial growth device of claim 8, wherein the heating bulb comprises a bulb holder and a bulb body fixed on the bulb holder, the bulb holder comprises a rotary lamp holder body and a rotary adjusting mechanism below the rotary lamp holder body, the bulb body is fixed on the bulb holder through the rotary lamp holder body, the rotary lamp holder body is driven to rotate through the rotary adjusting mechanism to control the bulb body to rotate on a plane vertical to the horizontal direction,

the adjusting module is specifically used for adjusting the angle formed by the bulb body and the horizontal direction through the rotary adjusting mechanism.

10. The epitaxial growth apparatus of claim 8, wherein,

the first preset angle is 3-5 degrees, and the second preset angle is 3-5 degrees.