CN219137005U

CN219137005U - Vertical film forming device capable of stably controlling temperature and improving wafer growth uniformity

Info

Publication number: CN219137005U
Application number: CN202320034064.8U
Authority: CN
Inventors: 刘鹏; 徐文立; 沈磊
Original assignee: Ningbo Hiper Vacuum Technology Co Ltd
Current assignee: Ningbo Hengpu Technology Co ltd
Priority date: 2023-01-06
Filing date: 2023-01-06
Publication date: 2023-06-06
Anticipated expiration: 2033-01-06

Abstract

The utility model discloses a vertical film forming device capable of stably controlling temperature and improving wafer growth uniformity, which comprises a reaction chamber, a multi-region temperature control mechanism and a specific point, wherein a thermal field in the reaction chamber is divided into an upper part and a lower part which are respectively used for preheating process gas and heating wafers, the thermal fields are all multi-region distributed, at least two temperature measuring elements are arranged at the top of the film forming device, the temperature of the center and the edge of the wafer is monitored in the film forming process, and the temperature is fed back to a control system to realize the temperature control output of the thermal field of a lower furnace body. The lower furnace body thermal field is close to the base heating body to heat the wafer in an auxiliary way, the upper furnace body thermal field is close to the air inlet chamber, the thermocouple at the air inlet chamber feeds back temperature data to control output power, the wafer is formed into a film to a certain film thickness to maintain the original thermal field output power, and the influence of temperature change caused by film interference on the normal film forming process is avoided.

Description

Vertical film forming device capable of stably controlling temperature and improving wafer growth uniformity

Technical Field

The utility model relates to the technical field of film forming devices, in particular to a vertical film forming device capable of stably controlling temperature and improving wafer growth uniformity.

Background

With the development of vapor phase epitaxy technology for semiconductor preparation, the film forming device has high-quality and high-efficiency film growth function. However, the uniformity of the surface temperature of the crystal in the conventional film forming apparatus cannot meet the requirement, and the temperature in the film forming apparatus cannot be adjusted in real time according to the film forming process of the wafer, so that the film forming quality of the wafer is not good enough.

Disclosure of Invention

The utility model aims to provide a vertical film forming device capable of stably controlling the temperature and improving the uniformity of wafer growth so as to solve the problems in the prior art, and the quality of the wafer after film formation can be obviously improved by improving the uniformity of the surface temperature of crystals in a reaction chamber and fully preheating the film forming process gas.

In order to achieve the above object, the present utility model provides the following solutions: the utility model provides a vertical film forming device capable of stably controlling temperature to improve the growth uniformity of wafers, which comprises

The reaction chamber is internally provided with an upper thermal field and a lower thermal field, the upper thermal field is arranged close to the air inlet chamber, and the lower thermal field is arranged close to the base heating body and is used for assisting in heating the wafer; and

the multi-region temperature control mechanism comprises a temperature measuring element and a control system, wherein the temperature measuring element is used for monitoring and recording the temperature of a specific point position in the reaction chamber, the temperature measuring element is electrically connected with the control system, and the control system is also used for regulating and controlling the power output of a base heating body and an upper thermal field; and

and the specific point positions comprise a center temperature measurement point and an outer ring temperature measurement point which are respectively positioned at the center and the edge of the wafer.

In one embodiment, the temperature measuring element is a radiation thermometer.

In one embodiment, the radiation thermometers are at least two in number, and the radiation thermometers are used for monitoring the temperatures of the central temperature measuring point and the outer ring temperature measuring point and feeding back temperature information to the control system.

In one embodiment, the radiation thermometer is mounted on the top of the outer side of the reaction chamber, and the radiation thermometer is used for monitoring the temperature of the central temperature measuring point and the outer ring temperature measuring point of the wafer surface through a window on the top of the reaction chamber.

In one embodiment, the specific point further comprises an intake chamber temperature measurement point located at an outlet of the intake chamber.

In one embodiment, the temperature sensing element further comprises a thermocouple for monitoring the temperature at the intake chamber temperature sensing point and feeding temperature information back to the control system.

In one embodiment, the substrate of the wafer is mounted on a base plate, and the peripheral portion of the substrate of the wafer is in direct contact with the base plate, the base plate being mounted on a susceptor, and the rotation driving mechanism is for driving the susceptor to rotate.

Compared with the prior art, the utility model has the following beneficial technical effects:

the utility model relates to a vertical film forming device capable of stably controlling temperature and improving wafer growth uniformity, which comprises a reaction chamber, a multi-region temperature control mechanism and a specific point location, wherein a thermal field in the reaction chamber is divided into an upper part and a lower part which are respectively used for preheating process gas and heating wafers, and the thermal field is multi-region distributed, at least two temperature measuring elements are arranged at the top of the film forming device, the temperature of the center and the edge of the wafer is monitored in the film forming process, and the temperature is fed back to a control system to realize the temperature control output of a thermal field of a lower furnace. The lower furnace body thermal field is close to the base heating body to heat the wafer in an auxiliary way, the upper furnace body thermal field is close to the air inlet chamber, the thermocouple at the air inlet chamber feeds back temperature data to control output power, the wafer is formed into a film to a certain film thickness to maintain the original thermal field output power, and the influence of temperature change caused by film interference on the normal film forming process is avoided.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present utility model, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a reaction chamber temperature sensing device;

FIG. 2 shows a temperature measurement point on the surface of a substrate;

FIG. 3 is a schematic diagram of the initial temperature measurement of the film formation growth stage;

FIG. 4 is a schematic diagram showing temperature measurement when the wafer film thickness reaches a certain value;

FIG. 5 is a schematic view of the interior light of the wafer of FIG. 4;

wherein 1 a radiation thermometer; 2, a control system; 3 an upper thermal field; 4, a substrate; 5 a main heater; 6 an auxiliary heater; 7 wafers; 8, a central temperature measurement point; 9, measuring the temperature of the outer ring; 10 thermocouples; 11 a rotary drive mechanism.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

In order that the above-recited objects, features and advantages of the present utility model will become more readily apparent, a more particular description of the utility model will be rendered by reference to the appended drawings and appended detailed description.

As shown in FIGS. 1-5, the present utility model provides a vertical film forming apparatus capable of stably controlling temperature to improve uniformity of wafer growth, comprising

A reaction chamber, wherein an upper thermal field 3 and a lower thermal field are arranged in the reaction chamber, the upper thermal field 3 is arranged close to the air inlet chamber, and the lower thermal field is arranged close to the base heating body and is used for auxiliary heating of the wafer 7; and

the multi-zone temperature control mechanism comprises a temperature measuring element and a control system 2, wherein the temperature measuring element is used for monitoring and recording the temperature of a specific point in the reaction chamber, the temperature measuring element is electrically connected with the control system 2, the control system 2 is also used for regulating and controlling the power output of a base heating element and an upper thermal field 3, the multi-zone heating device usually uses a plurality of temperature measuring elements to respectively measure the temperature of each zone, and the measured temperature is fed back to the control system 2 to regulate the output of each zone heating element; and

the specific points include a center temperature measurement point 8 and an outer ring temperature measurement point 9 located at the center and the edge of the wafer 7, respectively.

In one embodiment, the thermal field adopts a multi-zone temperature control mode to more conveniently realize uniform temperature of the wafer surface. The data of specific point positions are monitored and recorded by temperature measuring elements such as a common thermocouple, a thermometer and the like and are transmitted to the control system 2, and the power output of a heating element related to the measuring point positions is regulated and controlled, so that the temperature of each region is controllable. The temperature required to be reached in the film forming process is high, and the influence on the air flow is avoided, so that the radiation thermometer 1 is used for measuring the temperature. The radiation thermometer 1 measures the temperature of the surface of an object by measuring the intensity of infrared light or visible light emitted by the object.

In the film formation, the wafer 7 is mounted on the base plate 4 with the peripheral portion thereof in direct contact with the base plate 4, and the heat transfer at the temperature rise are different from those in the central portion of the wafer 7. The wafer 7 center and edge temperatures are monitored with at least two or more radiation thermometers 1. The epitaxial growth of the wafer 7 to a certain thickness is prone to film interference, resulting in errors in the measured temperature of the radiation thermometer 1. The radiation thermometer 1 receives infrared light or visible light radiated from the surface of the wafer 7, the film reaches a certain thickness, and the infrared light or visible light radiated from the lower surface of the wafer 7 interferes with the upper surface temperature measurement, so that the accurate temperature cannot be measured.

In one embodiment, the reactant gases in the reaction chamber of the vertical film forming apparatus flow down from the top inlet chamber to the surface of the substrate while heating the wafer substrate and the reactant gases to a reaction temperature and maintaining the substrate in high speed rotation as driven by the susceptor. The radiation thermometer 1 is installed on the top of the outside of the reaction chamber, and monitors the surface temperature of the wafer through a window. The specific point also comprises an air inlet chamber temperature measuring point, and the air inlet chamber temperature measuring point is positioned at the outlet of the air inlet chamber; a thermocouple 10 is mounted for measuring the temperature at the outlet of the inlet chamber.

In one of the embodiments, the substrate of the wafer 7 is mounted on the base plate 4, and the peripheral portion of the substrate of the wafer 7 is in direct contact with the base plate 4, the base plate 4 is mounted on a susceptor, and the rotation driving mechanism 11 is used to drive the susceptor to rotate.

The wafer 7 is heated mainly by a thermal field in the base, the heating body at the lower part of the upper furnace body is used for auxiliary heating, and the thermal field adjusts the output power according to the temperature measured on the surface of the wafer 7. And in the film forming process temperature rising part, the radiation thermometer 1 measures the temperatures at the center and the outer edge of the surface of the wafer, and feeds back the temperatures to the control system 2, and the output power of the thermal field is adjusted according to the temperature rising set value. The radiation thermometer 1 detects that the surface temperature of the wafer 7 reaches the reaction temperature, and the reaction gases such as a carbon source, a silicon source and the like are introduced, preheated by a thermal field and flow to the surface of the wafer substrate for reaction and deposition to form the silicon carbide film. The thermal field output power is substantially stable and is suitably adjusted in accordance with the surface temperature of the wafer 7 measured by the radiation thermometer 1.

The thermal field output power at the film forming stage is recorded, and when the film thickness reaches a thickness of 2 μm or more, the temperature measured by the radiation thermometer 1 is used as observation data only, and the thermal field output maintains the average value of the output power at the front stage of the film forming stage until the film forming is completed. The cooling section pauses the output of the heating body, the wafer 7 is carried out of the reaction chamber after reaching the transfer temperature, and a new substrate is loaded subsequently for the secondary film forming process or the process is stopped.

The outlet of the air inlet chamber is similar to the upper thermal field heating body, and the excessive temperature of the area can cause the reaction gas to be mixed and deposited at the air inlet end part to prevent the subsequent air inlet uniformity, and deposited particles fall on the surface of a wafer to generate film forming defects, so that the quality of the wafer is affected. A thermocouple 10 is additionally arranged near the outlet of the air inlet chamber to measure the temperature, and the output of the heating body of the upper furnace body is adjusted to prevent the temperature from being too high.

The vertical film forming device capable of stably controlling the temperature and improving the growth uniformity of the wafer has the characteristics that:

1. the top radiation thermometer 1 measures the temperature of the center and the outer ring of the wafer 7 respectively, and the temperature of the center and the outer ring of the wafer 7 is consistent by adjusting the output of the heating element in the film forming stage. The central heating element in the base is controlled by the central temperature of the wafer 7 to output power, and the heating elements in the inner ring and the outer ring of the base and the upper thermal field 3 of the reaction chamber are close to the heating element of the base and all determine the output power by the temperature of the outer ring of the wafer. The output power of the film growth stage in the film forming process is in dynamic balance.

2. The wafer film grows to a certain thickness to generate film interference, as shown in fig. 5, the light waves are respectively reflected by the upper and lower interfaces of the film, new light waves are formed due to mutual interference, and the measured data of the radiation thermometer 1 are different from the surface temperature of the actual wafer 7. So as to maintain the average value of the output power of the thermal field in each region in the stable growth stage of the front-stage film.

3. The temperature thermocouple is arranged at the air outlet end of the air inlet chamber to monitor the temperature of the area, so that the phenomenon that the output of a heating element close to the air inlet chamber is too high due to the fact that a thermal field close to the upper part of the reaction chamber is close to the heating element of the air inlet chamber, and the mixed gas at the air outlet end of the air inlet chamber is heated and reacts and deposits at the air outlet, and the subsequent air inlet uniformity is affected is avoided.

The vertical film forming device capable of stably controlling the temperature and improving the growth uniformity of the wafer controls the output power of a related thermal field by measuring the temperature of the inner ring and the outer ring of the surface of the wafer 7; the film forming process reaches the stage of stable growth of the wafer 7, the film thickness exceeds a set range, and the output power of the thermal field maintains the average power of stable growth in the front stage; a temperature measuring element is additionally arranged near the thermal field of the air inlet chamber for independent control.

It should be noted that it will be apparent to those skilled in the art that the present utility model is not limited to the details of the above-described exemplary embodiments, but may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the utility model being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

The principles and embodiments of the present utility model have been described in detail with reference to specific examples, which are provided to facilitate understanding of the method and core ideas of the present utility model; also, it is within the scope of the present utility model to be modified by those of ordinary skill in the art in light of the present teachings. In view of the foregoing, this description should not be construed as limiting the utility model.

Claims

1. A vertical film forming device capable of stably controlling temperature and improving the growth uniformity of wafers is characterized in that: comprising

2. The vertical film forming apparatus for improving uniformity of wafer growth by stably controlling temperature according to claim 1, wherein: the temperature measuring element adopts a radiation thermometer.

3. The vertical film forming apparatus for improving uniformity of wafer growth by stably controlling temperature according to claim 2, wherein: the radiation thermometer is used for monitoring the temperatures of the central temperature measuring point and the outer ring temperature measuring point and feeding back temperature information to the control system.

4. The vertical film forming apparatus for improving uniformity of wafer growth by stably controlling temperature according to claim 3, wherein: the radiation thermometer is arranged at the top of the outer side of the reaction chamber and is used for monitoring the temperature of a central temperature measuring point and an outer ring temperature measuring point of the surface of the wafer through a window at the top of the reaction chamber.

5. The vertical film forming apparatus for improving uniformity of wafer growth by stably controlling temperature according to claim 1, wherein: the specific point location further comprises an air inlet chamber temperature measuring point, and the air inlet chamber temperature measuring point is located at the outlet of the air inlet chamber.

6. The vertical film forming apparatus for improving uniformity of wafer growth by stably controlling temperature according to claim 5, wherein: the temperature measuring element further comprises a thermocouple for monitoring the temperature at the intake chamber temperature measuring point and feeding back temperature information to the control system.

7. The vertical film forming apparatus for improving uniformity of wafer growth by stably controlling temperature according to claim 1, wherein: the substrate of the wafer is mounted on a base plate, and the peripheral part of the substrate of the wafer is in direct contact with the base plate, the base plate is mounted on a pedestal, and a rotation driving mechanism is used for driving the pedestal to rotate.