CN1320157C - Chemical vapor deposition method of integrating heating and depositing of silicon slices - Google Patents

Abstract

The present invention relates to a chemical vapor deposition method of integrating heating and depositing of silicon slices into a whole body. The present invention comprises: the silicon slices are arranged on an electrode; the vacuum is formed by pumping; a silicon slice micro area is started for heating a controller power source; the silicon slices are directly used as a heating device; the silicon slice temperature is set; reactants are led or are added; the reactants carry out reaction on the surfaces of the silicon slices for producing products; the silicon slices are used as a base; as a result, the reactants are deposited on the surfaces of the silicon slices. A programmable silicon slice is adopted for heating a controller; thereby, the disadvantages when the silicon slices are used as the load of the heating device are overcome; a mode that the silicon slices are used for directly heating is adopted; the present invention has the advantages wide operational temperature range (the normal temperature of-1200 DEG C), flexible temperature control, rapid temperature variation (larger than 200 DEG C /S), accurate temperature control (the temperature fluctuation is less than 5 DEG C), and reinforcement in repeatability. Because the silicon slices have a small volume, the energy and the experiment space are saved; a plurality of silicon slices can also be arranged in the same system for independently controlling respective temperature; the flexibility of a CVD method is greatly widened.

Description

The chemical gaseous phase depositing process that integrates the silicon chip heating deposition

(1) technical field

The present invention relates to a kind of chemical vapor deposition (CVD) experimental technique that integrates the silicon chip heating deposition.

(2) background technology

Chemical vapor deposition (CVD) is to utilize gaseous substance to carry out chemical reaction at a solid surface, generates the process of solid deposited thing, is the new technology of the inorganic novel material of preparation that grew up in nearly 10 years.It has been widely used for the purification of material, new crystalline development, the numerous areas such as deposition of various monocrystalline, polycrystalline, vitreous state inorganic thin film or coating.In aforesaid method, no matter be pyrolytic reaction, chemosynthesis reaction, or chemical reactant transport, temperature control all is an important condition.And many reactions all concentrate on below 1200 ℃, and tube furnace then is a kind of type of heating that the most generally is sampled.But based on the characteristics in the tube furnace design, the shortcoming that exists some self to be difficult to overcome is low as power consumption big (majority is 2000W), capacity usage ratio; Thermal capacitance is big, temperature variation is slow; Product efficient is low; Center warm area temperature is subjected to influence of various factors such as vacuum tightness, gas flow rate, and temperature control is inaccurate, and is reduced gradually by middle mind-set two ends temperature.This is all incompatible with trend such as the environmental protectionization of present compound experiment, micro-ization, precision, high conversions, and especially temperature is handed over fast, temperature controls CVD experimental system accurately to needs, especially the deadly defect of tube furnace.

(3) summary of the invention

The object of the present invention is to provide a kind of direct employing silicon chip as well heater and chemical vapour deposition substrate, can control silicon temperature flexibly by program, can realize fast temperature change (greater than 200 ℃/S), integrate the chemical gaseous phase depositing process of silicon chip heating deposition.Can in an individual system, introduce a plurality of silicon chips in addition simultaneously and independently control temperature separately, set up the composite chemical CVD (Chemical Vapor Deposition) method of multiple material.

The step that integrates the chemical gaseous phase depositing process of silicon chip heating deposition is:

1) cuts the silicon chip of desired size, and place on two electrodes of reaction unit;

2) vacuumize the aerial stability of vacuum tightness visual response thing and product and deciding;

3) starting silicon chip microcell heating controller power supply, directly is heating unit with the silicon chip, sets silicon temperature, and numerical value is determined by the temperature of reaction that concrete chemical deposition reaction requires;

4) feeding or adding reactant;

5) reactant generates product at silicon chip surface generation chemical reaction;

6) with silicon chip as the sedimentary substrate of reactant, reaction product is deposited at silicon chip surface;

7) close silicon chip microcell heating controller power supply, close pumped vacuum systems;

8) silicon chip is taken out, the sedimentation products that obtains is carried out performance test.

Since the singularity of its structure of silicon chip and the stability under the high temperature, Chang Zuowei chemical vapour deposition substrate.But the special temperature profile of silicon chip (is semi-conductor during low temperature, high temperature is conductor down, from room temperature to 1200 ℃, resistance change is near four orders of magnitude), make it seldom be directly used in heating (heating power supply is difficult to adapt to so big load variations), and adopting passive type of heating more, this just produces above-mentioned variety of problems.And the present invention adopts program-controlled silicon chip heating control apparatus, overcome the shortcoming of silicon chip as heater load, abandoned the indirect heating mode (thereby promptly control the chemical vapour deposition substrate indirectly---the temperature of silicon chip) of conventional tube furnace by control tubular type furnace temperature, and the direct heating system of employing silicon chip self, but not only operating temperature range wide (normal temperature～1200 ℃), temperature control flexibly (but hand adjustment or program control), temperature variation rapidly (greater than 200 ℃/S), temperature precise control (temperature fluctuation is less than 5 ℃) has strengthened the repeatability of testing.And because the silicon chip volume is little, not only save energy (tube furnace is 2000W, and the present invention is 240W) and lab space can also be placed many silicon chips and independent its temperature separately of controlling in same system, and this has just widened the handiness of CVD method greatly.Moreover, adopting under the tube furnace mode, toward interior biography, necessary if silicon chip need be heated to 1000 ℃, outer field glass reaction tube just must bear and be higher than 1000 ℃ high temperature heat earlier through the glass outer reaction tubes, can only select the silica tube of high price for use by outer; And adopt silicon chip of the present invention from the thermal test system, when silicon chip reached 1000 ℃, the temperature that the glass outer reaction tubes is reached by the silicon chip thermal radiation was not higher than 400 ℃, can use the simple glass pipe fully, save experimentation cost, and brought many convenience for the processing of reaction tubes shape; Again because among the present invention, the glass tube walls temperature is far below silicon temperature, reactant can only react and deposits at silicon chip surface, and the efficient that silicon chip surface obtains sedimentation products improves; In addition, in the CVD test of adopting the tube furnace type of heating, because reaction tubes places in the tube furnace, the practical situation of reaction can't be observed, and adopt present method, and entire reaction course can see through Glass tubing and directly observe, convenience that this has also given test tape.

Below provide the performance comparison sheet of the CVD method of the present invention and conventional tube furnace heating:

	Adopt the CVD test method of tube furnace type of heating	The CVD method that integrates the silicon chip heating deposition
			Energy consumption	High	Low
Temperature rate	Slowly	Hurry up
			Temperature controlled accuracy	Low	To
Installation cost	High	Low
			The settling productive rate	Low	High
The test operability	Bad	Good

(4) description of drawings

Fig. 1 is the general chemical vapour deposition reaction process comparison diagram of the present invention and conventional tube furnace heating means.In Fig. 1, (a) be the present invention, (b) be conventional tube furnace heating means; 1 is reactant, and 2 is product, and 3 is glass tube walls, and 4 is silicon chip.

(5) embodiment

At first must design one and include two electrodes, can easily change the silicon chip on two electrodes, and vacuum-pumping, can feed the glass reaction device of reaction gas.The electrode two ends are with causing outside the vacuum systems, and are connected to program-controlled silicon chip microcell heating controller.

Cut the silicon chip of desired size then, and place on two electrodes of reaction unit; Vacuumize, the aerial stability of vacuum tightness visual response thing and product and deciding adopts mechanical pump (the minority chemical vapour deposition also can directly be carried out) more in air; Start silicon chip microcell heating controller power supply, configure silicon temperature; Feed or the adding reactant; Reactant generates product at silicon chip surface generation chemical reaction; Reaction product deposits at silicon chip surface; Close silicon chip microcell heating controller power supply and vacuum system power supply; Silicon chip is taken out, the sedimentation products that obtains is carried out performance test.

As shown in Figure 1, reaction general process of the present invention such as Fig. 1 (a) flow process:

A. reactant is moved to the heating silicon chip surface;

B. reactant reacts at silicon chip surface, is converted to product;

C. product is in silicon chip surface deposition (minority deposits at tube wall).

Fig. 1 (b) is the general reaction process under the conventional tube furnace type of heating:

D. reactant migrates to silicon chip and glass tube walls surface;

E. reactant is converted into product in glass tube walls and silicon chip surface;

F. product is in glass tube walls and silicon chip surface deposition.

More above-mentioned two reaction process are adopting under the tube furnace type of heating, because the glass reaction tube temperature is higher than silicon chip, so reactant can react at silicon chip surface, also can react in glass tube walls.And silicon area is minority much smaller than the glass reaction tube inner wall area so obtain sedimentation products at silicon chip surface, and reaction efficiency is lower.And in this test method, the glass tube walls temperature is far below the silicon chip surface temperature, and reactant can only react at silicon chip surface, and most of reaction product will directly deposit at silicon chip surface, have only only a few to migrate to the glass tube walls deposition, so present method can obtain higher productive rate.

Embodiment 1: the silicon chip surface nano SnO ₂Producing of array

Cut the silicon chip of 20mm * 5mm, be fixed on the electrode, start mechanical pump and vacuumize, treat that vacuum is stable after, start silicon chip microcell heating control apparatus, design temperature is 800 ℃, is buffering with the carbon tetrachloride gas, slowly feeds SnH ₄Gas, wait reaction to finish after, close silicon chip microcell heating control apparatus power supply and mechanical pump power supply, take out silicon chip.Can obtain SnO at silicon chip surface ₂Nano-array.This arrayed is neat, and quantity is a lot, under electric border as unbroken rice seedling shape.Control different SnH ₄Gas concentration and silicon temperature can also obtain the nano particle as multiple shapes such as chrysanthemum shapes.

Embodiment 2: silicon chip surface Mo ₂O ₃Producing of nano belt

Cut the silicon chip of 20mm * 5mm, be fixed on the electrode, start mechanical pump and vacuumize, treat that vacuum is stable after, start silicon chip microcell heating control apparatus, design temperature is 1000 ℃, the metal molybdenum powder is placed silicon chip surface heating and gasifying and deposition (can place silicon chip surface in advance before vacuumizing), wait reaction to finish after, close silicon chip microcell heating control apparatus power supply and mechanical pump power supply, take out silicon chip.Can obtain the molybdenum oxide nano belt, under electric border, observe, about 100: 10: 1 of the ratio of the length and width of band, thickness.Obtain the nano oxidized molybdenum particle of many other shapes in addition.

Embodiment 3: the producing of silicon chip surface nm gold particles (expanded application of the present invention)

Traditional silicon chip surface nm gold particles is produced needs to use porous silicon, and will make porous silicon and remarkable to the silicon single crystal disk (non-porous silicon) that direct purchase comes.This new heating technique temperature variation of present method utilization is characteristics rapidly, elder generation is at the silicon chip surface metal spraying of 5mm * 20mm, then silicon chip is fixed on the electrode, start silicon chip microcell heating controller power supply, design temperature is at 1100 ℃, cuts off the electricity supply after reaching temperature, the silicon chip annealing of lowering the temperature rapidly, can obtain the gold grain of 20～100nm at silicon chip surface, and gold grain distributes very even, continuous each other.The thickness and the annealing temperature of control metal spraying can also obtain the different gold grain of particle diameter.The size particles diameter is than generally being not more than 5/2.Thereby made good place mat for other CVD test.

Present method is used for ZnO in addition ₂Deng producing of nano particle, also obtained good effect.This method is also further extended to laser chemical vapor deposition system, microwave plasma chemical vapour deposition system etc.

Claims (1)

1, the chemical gaseous phase depositing process that integrates the silicon chip heating deposition is characterized in that the steps include:

1) cuts the silicon chip of desired size, and place on two electrodes of reaction unit;

2) vacuumize;

3) starting silicon chip microcell heating controller power supply, directly is heating unit with the silicon chip, sets silicon temperature;

4) feeding or adding reactant;

5) reactant generates product at silicon chip surface generation chemical reaction;

6) with silicon chip as the sedimentary substrate of reaction product, reaction product is deposited at silicon chip surface;

7) close silicon chip microcell heating controller power supply, close pumped vacuum systems;

8) silicon chip is taken out, the sedimentation products that obtains is carried out performance test.

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