CN205881883U - A cavity for epitaxial technology surface treatment of siC IGBT - Google Patents

Abstract

The utility model provides an introduced the infrared temperature probe below the bottom electrode that a cavity for epitaxial technology surface treatment of siC IGBT, but it is a steamed tungsten lamp pipe die piece of having introduced high temperature heating in traditional plasma etching cavity top, at the cavity. In manufacturing process is extended to siC IGBT device, carry out plasma etching and high temperature annealing processing to surface of the substrate earlier in this cavity, right rear cavity maintains the vacuum state and carries out epitaxial growth. Utilize plasma etching and high temperature annealing's method to handle to surface of the substrate before epitaxial growth, can obtain the surface of the substrate clean, level and smooth, that anti oxidability is strong to the crystal defect of substrate can be improved, the stress in the crystal is eliminated. Can sprout high -quality epitaxial layer on this kind of surface of the substrate, can play the yield of siC IGBT device product and wholeness and improve.

Description

A kind of cavity processed for SiC IGBT epitaxy technique surface

Art

This utility model relates to a kind of cavity processed for SiC IGBT epitaxy technique surface, belongs to semiconductor chip raw The technical field of product equipment.

Background technology

Along with the development of semiconductor technology, SiC material is with its distinctive big energy gap, high critical breakdown strength, high electricity The characteristic such as transport factor, high heat conductance, is more and more applied to the manufacturing of IGBT device.In SiC IGBT device In epitaxial process, the surface appearance of SiC substrate directly influences the quality of outer layer growth, thus has influence on IGBT device Overall performance.Substrate surface utilize before epitaxial growth the method for plasma etching and high annealing process, permissible Acquisition cleaning, the substrate surface that smooth, oxidation resistance is strong, and the crystal defect of substrate can be improved, eliminate in crystal Stress.This kind of substrate surface can grow high-quality epitaxial layer, yield and the overall performance to IGBT device product Serve and improve.

Summary of the invention

This utility model relates to a kind of cavity processed for SiC IGBT epitaxy technique surface, and concrete structure is: include Plasma etching cavity, described plasma etching cavity be provided above the halide-tungsten fluorescent lamp module for high-temperature heating, described etc. In ion etching cavity, the lower section of bottom electrode arranges infrared temperature probe.

The above-mentioned cavity processed for SiC IGBT epitaxy technique surface, wherein: described halide-tungsten fluorescent lamp module contains number Individual halide-tungsten fluorescent lamp arranged in arrays.

The above-mentioned cavity processed for SiC IGBT epitaxy technique surface, wherein: described infrared temperature probe quantity is 9 Individual, described infrared temperature probe crystal circle center along plasma etching cavity is uniformly distributed to edge direction with radial.

The above-mentioned cavity processed for SiC IGBT epitaxy technique surface, wherein: the one of described plasma etching cavity Side arranges controllable magnetic field, process gas passage, mass flow controller, and opposite side arranges controllable magnetic field；Described plasma etching It is provided with bottom electrode among cavity, described bottom electrode arranges thimble, described thimble is placed wafer；Described plasma etching cavity Lower section ground connection, radio-frequency signal generator, gas passage are set.

The above-mentioned cavity processed for SiC IGBT epitaxy technique surface, wherein: set gradually on described gas passage Barometer, valve valve, choke valve, molecular pump, isolating valve, dry pump.

Surface before SiC IGBT device epitaxial growth processes and epitaxial growth is to maintain vacuum state even in this cavity Continue and carry out, before IGBT device epitaxial growth, in this cavity, substrate surface is carried out plasma etching and the high temperature anneal, should In cavity, substrate surface is carried out plasma etch processes, be first passed through process gas CHF₃ 50sccm、Ar 20sccm、He 20sccm, the Stress control in cavity is at 30mTorr, and radio frequency output 60W, the time of reaction is 30s；Be passed through again Ar 50sccm, He 50sccm, the Stress control in cavity is at 20mTorr, radio frequency output 50W, response time 20 s.Plasma etching surface After reason terminates, maintaining vacuum state in cavity, wafer is slowly heated to 1200 by halide-tungsten fluorescent lamp module^oC, keeps constant temperature 5min, is slowly dropped to room temperature the most again and completes annealing.

The cavity processed for SiC IGBT epitaxy technique surface of this utility model design, is to carve at traditional plasma Erosion cavity introduced above can the halide-tungsten fluorescent lamp module of high-temperature heating, below the bottom electrode of cavity, introduce infrared temperature visit Head.In SiC IGBT device extension manufacturing process, in this cavity, first substrate surface can be carried out plasma etching and height Temperature annealing, then cavity maintains vacuum state to carry out epitaxial growth.

In the manufacturing process of SiC IGBT device, can there are various pollutant in its substrate surface, such as oxide, granular powder Dirt, Organic substance, metal impurities and ion etc., surface roughness is higher, and crystal exists a certain degree of defect and stress.This Under situation growth epitaxial layer quality poor, IGBT device resistance value can be caused to uprise, electron mobility reduce, switching loss change Greatly, the problem such as switching speed is slack-off, badly influence the performance of IGBT device.Used before SiC IGBT device epitaxial growth The process for treating surface of this utility model design, can improve the surface appearance of substrate and the growth matter of epitaxial layer largely Amount, thus improve yield and the overall performance of IGBT device product.

Current SiC IGBT extension processing technology, the surface of substrate processes and epitaxial growth is typically at different equipment Carry out with in cavity, substrate surface may be caused secondary pollution, and the yield of equipment can be affected.This utility model sets The technical scheme of meter, makes the surface before epitaxial growth process and epitaxial growth can maintain vacuum state even in same cavity Continue and carry out, solve the problems referred to above.

Accompanying drawing explanation

The cavity schematic diagram that the epitaxy technique surface of Fig. 1 this utility model design processes:

1-halide-tungsten fluorescent lamp module in figure, 2-mass flow controller, 3-quartz window, 4-controllable magnetic field, 5-bottom electrode, 6-pushes up Pin, 7-ground connection, 8-infrared temperature probe, 9-radio-frequency signal generator, 10-barometer, 11-gate valve, 12-choke valve, 13-molecule Pump, 14-isolating valve, 15-dry pump.

Fig. 2 halide-tungsten fluorescent lamp module diagram:

16-halide-tungsten fluorescent lamp in figure, 17-lampshade, 18-cavity cover plate.

Fig. 3 infrared temperature probe scattergram:

5-bottom electrode in figure, 8-infrared temperature is popped one's head in.

Detailed description of the invention

As it is shown in figure 1, traditional plasma etching cavity introduced above can the halide-tungsten fluorescent lamp module 1 of high-temperature heating, Infrared temperature probe 7 is introduced below the bottom electrode 5 of cavity.Halide-tungsten fluorescent lamp module 1 above cavity is contained within numerous in matrix The halide-tungsten fluorescent lamp of arrangement, as shown in Figure 2.Halide-tungsten fluorescent lamp luminescence is radiated at crystal column surface and can be heated to wafer more than 1000^oC Temperature.It is provided with 9 infrared temperature probes 8 below bottom electrode 5 to be uniformly distributed with radial along crystal circle center to edge direction, as Shown in Fig. 3.The thermal radiation signal of wafer is reached temperature control system by optical fiber and is converted into the signal of telecommunication and carries out point by infrared temperature probe 8 Analysis temperature control.

Before SiC IGBT device epitaxial growth, wafer is sent to this utility model design cavity in first to substrate Surface processes, and then maintains vacuum state to carry out epitaxial growth in cavity.Step and technique that surface processes are as follows:

1. by the method for plasma etching, substrate surface is carried out Soft lithograph, the dirt such as oxide removing substrate surface Dye thing.

First it is passed through process gas: CHF₃50sccm, Ar 20sccm, He 20sccm, the Stress control in cavity exists 30mTorr.After air-flow in cavity and pressure stability, radio-frequency signal generator 9 radio frequency providing power to be 60W excites Gas ions is reacted at crystal column surface, and the time of reaction is set to 30s.Under the effect of radio frequency, it is in the reaction cavity of fine vacuum Process gas dissociation ionization: CHF₃ + Ar + He + 3e→CF₃ ⁺ + CF3 + HF + F + Ar⁺ + He⁺。CF₃It is to carve Erosion SiO₂Chief active base, with SiO₂There is chemical reaction: 4CF₃ + 3SiO₂→3SiF₄↑+ 2CO₂↑+ 2CO↑.In reaction During, Ar⁺、CF₃ ⁺、He⁺ Simultaneously work as the effect of physical sputter etch.CHF₃The selection to substrate Si C etching can be improved Ratio, He can improve the uniformity of etching as diluent.

Being passed through Ar 50sccm, He 50sccm the most again, Stress control is in 20mTorr, radio frequency output 50W, response time 20 s.Use Ar⁺Before ise is removed, reaction generates at the carbon of substrate surface and polymer.

2., after Soft lithograph terminates, maintain vacuum state in cavity, substrate surface is carried out high annealing.Halogen tungsten lamp pipe die Wafer is slowly heated to 1200 by block 1^oC, keeps constant temperature 5min, is slowly dropped to room temperature the most again and completes annealing.

From the foregoing, this utility model design epitaxy technique surface process technology, have substrate surface damage little, The advantage that pollutant cleaning is thoroughly, surface roughness reduces, crystal defect and stress effectively eliminate, can significantly improve extension The quality of layer growth, thus improve yield and the overall performance of SiC IGBT device product.

Claims (5)

1. the cavity processed for SiC IGBT epitaxy technique surface, including plasma etching cavity, it is characterised in that: Described plasma etching cavity be provided above the halide-tungsten fluorescent lamp module for high-temperature heating, in described plasma etching cavity under The infrared temperature that arranges of the lower section of electrode is popped one's head in.

2. the cavity processed for SiC IGBT epitaxy technique surface as claimed in claim 1, it is characterised in that: described halogen Tungsten fluorescent tube module contains several halide-tungsten fluorescent lamp arranged in arrays.

3. the cavity processed for SiC IGBT epitaxy technique surface as claimed in claim 2, it is characterised in that: described red Outer temperature probe quantity is 9, described infrared temperature probe crystal circle center along plasma etching cavity to edge direction with Radial it is uniformly distributed.

4. the cavity processed for SiC IGBT epitaxy technique surface as claimed in claim 3, it is characterised in that: described etc. The side of ion etching cavity arranges controllable magnetic field, process gas passage, mass flow controller, and opposite side arranges controllable magnetic ?；It is provided with bottom electrode among described plasma etching cavity, described bottom electrode arranges thimble, described thimble is placed wafer； The lower section of described plasma etching cavity arranges ground connection, radio-frequency signal generator, gas passage.

5. the cavity processed for SiC IGBT epitaxy technique surface as claimed in claim 4, it is characterised in that: described gas Barometer, valve valve, choke valve, molecular pump, isolating valve, dry pump is set gradually on body passage.