A substrate heater

Abstract

A substrate heater for MBE equipment primarily comprises an outer frame, a fixed top plate, an upper thermal insulation plate, side thermal insulation rings, a lower thermal insulation plate, an inner ring of heating wires, and an outer ring of heating wires. This invention utilizes a dual-heat zone heating method generated by inner and outer heating wires, which can improve the heating temperature uniformity of the substrate, increase the molecular beam epitaxy reaction rate, and significantly increase the crystal growth quality and rate, thereby improving production efficiency and reducing production costs. The parallel arrangement of multiple layers of thermal insulation plates effectively reduces heat dissipation from the sample stage heating wires to the interior of the chamber, minimizing thermal impact on other components within the MBE chamber and ensuring MBE operational performance.

Description

Technical Field

[0001] The invention belongs to radiation heating equipment, and in particular relates to a substrate heater applied to MBE equipment. Technical Background

[0002] The basic principle of molecular beam epitaxy (MBE) is to -10 In a single-cell (MBE) system, a substrate and multiple molecular beam source furnaces (ejector furnaces) are placed relative to each other. Various components and dopant elements are introduced into separate ejector furnaces and heated within the furnaces, causing their molecules (or atoms) to be ejected onto the heated substrate surface at a specific thermal velocity and beam intensity ratio. These molecules interact with the surface, undergoing surface migration, decomposition, adsorption, and desorption, leading to epitaxial growth of single-crystal thin films. Bell Labs proposed a MBE sample stage design that uses tantalum filaments as radiative heaters, capable of heating 2-inch silicon wafers to temperatures ranging from 1200°C, with a total filament power of 600W. The research also explored placing a silicon diffuser between the tantalum heating filaments and the substrate, which can achieve better heat flux control and improved lattice quality after epitaxy. A cross-arranged dual-resistance filament arrangement was employed to control the radiative heat flux generated by resistive heating, regulating the heat flux across the substrate's temperature range. The research also verified stability under different temperature ranges, demonstrating excellent temperature uniformity across the substrate, from a low temperature of 780°C to a high temperature of 1200°C. The sample stage proposed by the University of Pennsylvania replaces the indium support with an indium-free support and adds a water cooling kit to prevent high temperatures from affecting other components within the chamber. Veeco proposes adding a backing ring around the substrate to compensate for heat flow conducted from the substrate edge, achieving higher temperature uniformity.

[0003] Since the inception of molecular beam epitaxy (MBE) technology, continuously improving sample stage performance has been a goal pursued by various research institutions. Temperature control, the most crucial component influencing the quality of epitaxial growth on substrates, is also a key issue. The primary challenges and challenges currently exist in achieving maximum area-percentage temperature uniformity and minimum temperature differences for sample stage heating systems of various sizes and formats. Summary of the Invention

[0004] In order to solve the problems of substrate heaters of MBE equipment in the prior art and achieve the maximum area percentage temperature uniformity and the minimum value of the limit temperature difference, the present invention provides a substrate heater for MBE equipment, comprising an outer frame (1), a fixed top plate (2), an upper heat insulation plate (3), a side heat insulation ring (4), a lower heat insulation plate (5), an inner ring hot wire (6), an outer ring hot wire (7), a mounting shaft (8), a fixed molybdenum wire (9), an electrode (10) and a spacer (11), characterized in that: the outer frame (1) is a cylindrical integral structure, the fixed top plate (2) is fixedly connected to and covers the upper end surface of the outer frame (1); the upper heat insulation plate (3) is fixed to the fixed top plate (2) by the mounting shaft (8), separated by the spacer (11), and arranged in parallel from top to bottom; the side heat insulation ring (4) is fixed to the outer frame (1) by the fixed molybdenum wire (9), and is arranged concentrically and spaced from inside to outside; a plurality of mounting shafts (8) The fixed top plate (2) is passed through in parallel with the upper heat insulation plate (3) and is fixed thereto; a plurality of fixed molybdenum wires (9) are passed through the outer frame (1) and are fixed to the side heat insulation ring (4); the lower heat insulation plate (5) is fixedly connected to and covers the lower end face of the outer frame (1); an upper heat insulation space is formed between the fixed top plate (2) and the upper heat insulation plate (3); a side heat insulation space is formed between the side heat insulation ring (4) and the outer frame (1); and a heat insulation space is formed between the lower heat insulation plate (5) and the inner ring heat wire (6) and the outer ring heat wire (7). The lower heat insulation space is formed between the mounting shafts (8); the spacer ring (11) passes through the through hole of the mounting shaft (8) corresponding to the mounting shaft (8), and is spaced and distributed between the through holes of the mounting shaft (8) corresponding to the upper heat insulation plate (3); the inner circle heating wire (6) adopts a meandering spiral arrangement mode, and the outer circle heating wire (7) adopts a concentric circle arrangement mode; the inner circle heating wire (6) and the outer circle heating wire (7) are concentrically fixed by multiple electrodes (10) and are parallel to the fixed top plate (2), forming a dual temperature zone arrangement.

[0005] Furthermore, the side wall of the outer frame (1) is provided with circumferentially uniformly distributed gap holes (1A), its upper end surface has three circumferentially uniformly distributed upper end surface grooves (1B), and its lower end surface has six circumferentially uniformly distributed grooves (1C); the fixed top plate (2) is disc-shaped, and its surface has through holes arranged in an array uniformly distributed in concentric circles, and has a through hole (2A) for the mounting shaft (8) and a through hole (2B) for the electrode (10), and three flanges (2C) are uniformly distributed in the outer diameter circumference, which cooperate with the upper end surface groove (1B) of the outer frame (1), and are fixedly connected to and cover the upper end surface groove (1B) of the outer frame (1); the upper heat insulation plate (3) is disc-shaped, and its surface has through holes uniformly distributed in an array, and has a through hole (3A) for the mounting shaft (8) and a through hole (3B) for the electrode (10), and the position of each through hole is consistent with the through hole (2A) of the fixed top plate (2). (2B) positions correspond one to one; the side heat-insulating ring (4) is cylindrical, and its side wall surface has gap holes (4A) uniformly distributed in the circumferential direction, and its gap holes (4A) are distributed in a similar manner to the gap holes (1A) of the outer frame (1); the fixed molybdenum wire (9) passes through the gap holes (1A) of the outer frame (1) and the gap holes (4A) of the side heat-insulating ring (4), realizing a fixed connection setting with concentric spacing from the inside to the outside; the mounting shaft (8) passes through the mounting shaft (8) through hole (2A) of the fixed top plate (2) in parallel, and is connected to the mounting shaft (8) through hole (3A) corresponding to the upper heat-insulating plate (3); the fixed molybdenum wire (9) passes through the gap hole (1A) of the outer frame (1), and is connected to the gap hole (4A) corresponding to the side heat-insulating ring (4); the electrode (10) passes through the electrode (10) through hole (2B) of the fixed top plate (2) in parallel, and is connected to the inner ring hot wire (6) The electrode contacts the through hole (6A) and the electrode contacts the through hole (7A) of the outer ring heating wire (7).

[0006] Furthermore, the upper heat insulation plate (3) is configured as a three-layer structure, and the multi-layer structure can effectively reduce the heat dissipation of the sample stage heating wire heat source to the interior of the cavity.

[0007] Furthermore, insulating ceramics are provided at the through-hole positions of the four electrodes (10) of the aforementioned fixed top plate (2); and gaskets are provided at the through-hole positions of each mounting shaft (8) of the fixed top plate (2).

[0008] The advantage of the present invention is that the dual-heat zone heating method generated by the internal and external dual heating wire layout can improve the heating temperature uniformity of the substrate sheet. The parallel arrangement design of multiple layers of thermal insulation boards is adopted to effectively reduce the heat dissipation of the sample stage heating wire heat source to the inside of the cavity, reduce the thermal impact on other components in the MBE cavity, and ensure the MBE operating performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is an overall schematic diagram of the present invention.

[0010] Figure 2 It is a cross-sectional schematic diagram of the present invention.

[0011] Figure 3 Schematic diagram of the structure of the outer frame.

[0012] Figure 4 Schematic diagram of the structure of the fixed top plate.

[0013] Figure 5 Schematic diagram of the structure of the upper insulation board.

[0014] Figure 6 It is a structural diagram of the side insulation ring.

[0015] Figure 7 Schematic diagram of the structure of the inner circle hot wire.

[0016] Figure 8 Schematic diagram of the structure of the outer ring hot wire. DETAILED DESCRIPTION

[0017] The present invention is further described below with reference to the accompanying drawings and examples.

[0018] like Figure 1-8 As shown, a substrate heater for MBE equipment mainly includes an outer frame 1, a fixed top plate 2, an upper thermal insulation plate 3, a side thermal insulation ring 4, a lower thermal insulation plate 5, an inner ring hot wire 6, an outer ring hot wire 7, a mounting shaft 8, a fixed molybdenum wire 9, an electrode 10 and a spacer 11; the outer frame 1 is a cylindrical integral structure, and the fixed top plate 2 is fixedly connected to and covers the upper end surface of the outer frame 1; the upper thermal insulation plate 3 is fixed to the fixed top plate 2 by the mounting shaft 8, separated by the spacer 11, and arranged in parallel from top to bottom; the side thermal insulation ring 4 is fixed to the outer frame 1 by the fixed molybdenum wire 9, and is arranged concentrically from the inside to the outside; multiple mounting shafts 8 pass through the fixed top plate 2 and the upper thermal insulation plate 3 in parallel and are fixed; multiple fixed molybdenum wires 9 passes through the outer frame 1 and is fixed to the side insulation ring 4; the lower insulation plate 5 is fixedly connected and covers the lower end surface of the outer frame 1; the upper insulation space is formed between the fixed top plate 2 and the upper insulation plate 3; the side insulation space is formed between the side insulation ring 4 and the outer frame 1; the lower insulation space is formed between the lower insulation plate 5 and the inner ring hot wire 6 and the outer ring hot wire 7; the spacer 11 passes through the through hole of the mounting shaft 8 corresponding to the mounting shaft 8, and is spaced between the through holes of the mounting shaft 8 corresponding to the upper insulation plate 3; the inner ring hot wire 6 adopts a meandering spiral arrangement, and the outer ring hot wire 7 adopts a concentric circle arrangement; the inner ring hot wire 6 and the outer ring hot wire 7 are concentrically fixed by multiple electrodes 10, parallel to the fixed top plate 2, forming a dual temperature zone arrangement.

[0019] The side wall of the aforementioned outer frame 1 is provided with circumferentially uniformly distributed gap holes 1A, its upper end surface has three circumferentially uniformly distributed grooves 1B, and its lower end surface has six circumferentially uniformly distributed upper end surface grooves 1C; the fixed top plate 2 is disc-shaped, and the surface has through holes arranged in an array uniformly distributed in concentric circles, with a through hole 2A for the mounting shaft 8 and a through hole 2B for the electrode 10, and three flanges 2C are uniformly distributed circumferentially on the outer diameter, which cooperate with the upper end surface groove 1B of the outer frame 1, and are fixedly connected to and cover the upper end surface groove 1B of the outer frame 1; the upper heat insulation plate 3 is disc-shaped, and the surface has through holes arranged in an array uniformly distributed, with a through hole 3A for the mounting shaft 8 and a through hole 3B for the electrode 10, and the position of each through hole is consistent with the through hole 2A, 2B positions correspond one to one; the side insulation ring 4 is cylindrical, and its side wall surface has circumferentially uniformly distributed gap holes 4A, and its gap holes 4A are distributed in a manner equivalent to the gap holes 1A of the outer frame 1, and the fixed molybdenum wire 9 passes through the gap holes 1A of the outer frame 1 and the gap holes 4A of the side insulation ring 4, realizing a fixed connection setting with concentric spacing from the inside to the outside; the mounting shaft (8) passes through the mounting shaft 8 through hole 2A of the fixed top plate 2 in parallel, and is connected to the mounting shaft 8 through hole 3A corresponding to the upper insulation plate 3; the fixed molybdenum wire 9 passes through the gap hole 1A of the outer frame 1, and is connected to the gap hole 4A corresponding to the side insulation ring 4; the electrode 10 passes through the electrode 10 through hole 2B of the fixed top plate 2 in parallel, and is connected to the electrode contact through hole 6A of the inner ring hot wire 6 and the electrode contact through hole 7A of the outer ring hot wire 7.

[0020] The aforementioned upper heat insulation plate 3 is configured as a three-layer structure. The multi-layer structure can effectively reduce the heat dissipation of the sample stage heating wire heat source to the interior of the cavity.

[0021] Insulating ceramics are provided at the through-hole positions of the four electrodes 10 of the aforementioned fixed top plate 2 ; and gaskets are provided at the through-hole positions of each mounting shaft 8 of the fixed top plate 2 .

[0022] The above description is only illustrative of the present invention and not restrictive. It is understood by those skilled in the art that changes, modifications or equivalents may be made based on the above disclosure without departing from the spirit and scope defined by the claims, and all of these will fall within the scope of protection of the present invention.

Claims

1. A substrate heater, comprising an outer frame (1), a fixed top plate (2), an upper heat insulation plate (3), a side heat insulation ring (4), a lower heat insulation plate (5), an inner ring heating wire (6), an outer ring heating wire (7), a mounting shaft (8), a fixed molybdenum wire (9), an electrode (10) and a spacer (11), characterized in that: The outer frame (1) is a cylindrical integral structure, and the fixed top plate (2) is fixedly connected to and covers the upper end surface of the outer frame (1); the upper heat insulation plate (3) is fixed to the fixed top plate (2) through a mounting shaft (8), separated by a spacer (11), and arranged in parallel from top to bottom; the side heat insulation ring (4) is fixed to the outer frame (1) through a fixed molybdenum wire (9), and is arranged concentrically from the inside to the outside; multiple mounting shafts (8) pass through the fixed top plate (2) and are fixed to the upper heat insulation plate (3); multiple fixed molybdenum wires (9) pass through the outer frame (1) and are fixed to the side heat insulation ring (4); the lower heat insulation plate (5) is fixedly connected to and covers the lower end surface of the outer frame (1); the fixed top plate (2) and the upper heat insulation plate (3) are fixed to each other. The upper heat insulation space is formed between the side heat insulation ring (4) and the outer frame (1); the lower heat insulation space is formed between the lower heat insulation plate (5) and the inner ring heat wire (6) and the outer ring heat wire (7); the spacer (11) passes through the through hole of the mounting shaft (8) corresponding to the mounting shaft (8) and is spaced and distributed between the through holes of the mounting shaft (8) corresponding to the upper heat insulation plate (3); the inner ring heat wire (6) adopts a meandering spiral arrangement mode, and the outer ring heat wire (7) adopts a concentric circle arrangement mode; the inner ring heat wire (6) and the outer ring heat wire (7) are fixed concentrically by multiple electrodes (10) and are parallel to the fixed top plate (2) to form a double temperature zone arrangement, and the upper heat insulation plate (3) is set as a three-layer structure.

2. The substrate heater according to claim 1, wherein: The side wall of the outer frame (1) is provided with circumferentially uniformly distributed gap holes (1A), and its upper end surface has three circumferentially uniformly distributed upper end surface grooves (1B), and its lower end surface has six circumferentially uniformly distributed grooves (1C); the fixed top plate (2) is disc-shaped, and its surface has through holes arranged in an array uniformly distributed in concentric circles, and has a through hole (2A) for a mounting shaft (8) and a through hole (2B) for an electrode (10), and three flanges (2C) are uniformly distributed in the outer diameter circumference, which cooperate with the upper end surface groove (1B) of the outer frame (1), and are fixedly connected to and cover the upper end surface groove (1B) of the outer frame (1); the upper heat insulation plate (3) is disc-shaped, and its surface has through holes uniformly distributed in an array, and has a through hole (3A) for a mounting shaft (8) and a through hole (3B) for an electrode (10), and the position of each through hole corresponds one-to-one to the position of the through hole (2A) (2B) of the fixed top plate (2); The heat ring (4) is cylindrical, and its side wall surface has circumferentially uniformly distributed gap holes (4A), and the gap holes (4A) are distributed in a similar manner to the gap holes (1A) of the outer frame (1). The fixed molybdenum wire (9) passes through the gap holes (1A) of the outer frame (1) and the gap holes (4A) of the side heat insulation ring (4), realizing a fixed connection setting with concentric spacing from the inside to the outside; the mounting shaft (8) passes through the mounting shaft (8) through hole (2A) of the fixed top plate (2) in parallel, and is connected to the mounting shaft (8) through hole (3A) corresponding to the upper heat insulation plate (3); the fixed molybdenum wire (9) passes through the gap hole (1A) of the outer frame (1) and is connected to the gap hole (4A) corresponding to the side heat insulation ring (4); the electrode (10) passes through the electrode (10) through hole (2B) of the fixed top plate (2) in parallel, and is connected to the electrode contact through hole (6A) of the inner ring heat wire (6) and the electrode contact through hole (7A) of the outer ring heat wire (7).

3. The substrate heater according to claim 1 or 2, wherein: Insulating ceramics are respectively provided at the through-hole positions of the four electrodes (10) of the fixed top plate (2); and gaskets are respectively provided at the through-hole positions of the respective mounting shafts (8) of the fixed top plate (2).

Images