CN1326215C

CN1326215C - Glass passivating process of silicon semiconductor device

Info

Publication number: CN1326215C
Application number: CNB2004100417162A
Authority: CN
Inventors: 林立强
Original assignee: CETC 55 Research Institute
Current assignee: CETC 55 Research Institute
Priority date: 2004-08-17
Filing date: 2004-08-17
Publication date: 2007-07-11
Anticipated expiration: 2024-08-17
Also published as: CN1599037A

Abstract

The present invention relates to glass passivation technology for a silicon semiconductor device, which is characterized in that a, various oxides and hydroxides or carbonate corresponding to the oxides for preparing passivation glass are manufactured into super fine powder with the granulate diameter which is smaller than or equal to 1 mu m so as to be used as raw material; b, after high temperature sintering, the formed passivation glass is manufactured into the super fine powder with the granulate diameter which is smaller than or equal to 1 mu m again so as to be used as powdered glass of a passivation device; c, when glass is passivated and thermally formed, the glass is heated at the low vacuum of 10 to 10<-1>Pa. The technology of the present invention can be used for preparing glass passivation films with the advantages of good evenness, basic elimination of various fine defects, low inner stress, good brim integrity of patterns etched on window holes, and high precision so as to reduce the high temperature reverse leakage current of the glass passivation device and increase the rate of finished products and reliability.

Description

Silicon semiconductor device glassivation technology

Technical field

The invention belongs to semiconductor device surface passivating technique field, be mainly used in the silicon semiconductor device surface passivation.

Background technology

For high pressure, high-power or do not have an encapsulation silicon semiconductor device, tend to adopt technology for passivating glass for obtaining high reliability more, this mainly is that glassivation has the function of following uniqueness to determine:

Barrier effect: the glassivation film is compared with silicon dioxide film, and compact structure is so have stronger anti-water, protection against the tide and stop that other foreign ion stains the performance of infiltration.

Resorption: the glass that is in the melting state in high temperature passivation thermoforming process has higher affinity and solid solubility for the metal impurities that fall to silicon face, thereby can reach the effect that abundant absorption is stained.

Radiation resistance: because the passivation glass compact structure, the cation that is in network calking state is many to be made up of contents of many kinds of heavy metal ion, so stronger radiation resistance is arranged.

Thick film is to the mitigation of external electric field: the thermal coefficient of expansion of glassivation film can quite mate with silicon, thus can make thick film, like this it can overcome since passivating film outside electric charge in the influence of semiconductor surface induction opposite charges.

Charge effect in the film: suitably select the component and the thermoforming condition of passivation glass, can make glass-film have positive or negative charge effect, so it can control the state of charge of semiconductor surface, improve the surface withstand voltage of device effectively.

Sodium ion trap and depressor effect: form in the ion in glass network, the ion that has can form electronegative fixed center, this negative electricity center can attract to be in the alkali metal ion of the positively charged of calking state, make it to be in the state that falls into that is subjected to, while network adjustment ion, because its adding, the network gap will be filled closelyr, and the activity space of free alkali metal ion and migration are blocked.

In sum, the effect of glassivation also depends on the characteristic of its micro-structural except depending on the composition that constitutes it, in order to reach above-described good passivation effect, the micro-structural that passivating film is made in requirement should be very perfect, and is flawless substantially and very uniform.

But the preparation method of existing passivation glass and the general similar part of glass, ceramic process are to use conventional granularity each type oxide of big (as Φ 3 μ m～Φ 5 μ m) or corresponding hydroxide, carbonate powder, form through the constant-pressure and high-temperature sintering, its raw-material granularity and grain shape can influence raw-material surface activity largely, thereby directly have influence on uniformity, volume density, the voidage of manufactured goods, and the completeness of solid phase reaction etc.So passivation glass film with general technology manufacturing, its microstructure comprises multiple crystalline phase, glassy phase, gap phase, gas phase (bubble) and various impurity, defective, micro-crack and undesirable brilliant Jie's feature etc., thereby is a kind of incomplete structure.Relate to above-mentioned glassivation principle and function, we are understood that the incomplete or defective glassivation film of micro-structural will directly influence the further processing of semiconductor postchannel process such as passivation effect and photoetching to it.

Summary of the invention

The objective of the invention is to overcome the deficiencies in the prior art part; adopt new technology to prepare micro-structural passivation glass film perfect, flawless substantially, good uniformity; improve the passivation protection performance significantly; improve the precision of postchannel process significantly, expand glassivation device application field its processing.

Its know-why and method are as follows:

For reaching above purpose, the present invention carries out meticulous reprocessing by the granularity to the raw material powder of preparation passivation glass, make its particle diameter less than 1 μ m (preferred≤100nm); Passivation glass powder synthetic behind the high temperature sintering is carried out once more retrofit, make its particle diameter less than 1 μ m (preferred≤100nm).

The low vacuum heat treatment technics of the present invention during also by the glassivation thermoforming controlled passivation effect, optimizes its performance.

The present invention can reach by following technical measures:

A. will preparing the various oxide powders of passivation glass or corresponding hydroxide or carbonate, to make particle diameter (preferred≤100nm) super fine less than 1 μ m.

B. make particle diameter less than 1 μ m (ultra-fine passivation glass micro mist preferably≤100nm) through synthetic passivation glass being pulverized again behind the high temperature sintering.

C. when the glassivation thermoforming, adopt 10-10 ^-1The heat treatment of Pa low vacuum.

Advantage of the present invention:

It is (preferred≤100nm) super fine less than 1 μ m that the native oxide of preparation passivation glass or corresponding hydroxide or carbonate powder are made particle diameter; Will through passivation glass synthetic behind the high temperature sintering pulverize again make particle diameter less than 1 μ m (preferred≤100nm) as the passivation glass powder.This twice meticulous powder machining process improves the surface activity of material greatly, and the completeness of solid phase reaction and the uniformity of manufactured goods increase substantially when making glass sintering or device passivation thermoforming.

The gap that the synthesis result that low vacuum heat treatment technics when using above-mentioned technical method with passivation (making intension gas be forced to diffusion at the micropore of thermoforming process by corresponding connection overflows) combines makes the passivation glass film mutually, gas phase, microdefect, and undesirable brilliant Jie's defective etc. is basic eliminates, and the integrality of passivating film is improved greatly.

The use of above technology descends the temperature of glassivation thermoforming significantly, and the range of decrease can reach 80 ℃-150 ℃, has reduced the harmful effects such as contamination under the high temperature relatively.

Above final effect significantly improves the quality of glassivation film.The glass-film good uniformity, various microdefects disappear substantially, and internal stress reduces, and back road photoetching process etching pattern edge integrality is good, precision is high, and device high temperature reverse leakage current reduces, and the rate of finished products and the reliability of device all get a promotion.

Embodiment

Embodiment 1: transwitch diode glassivation technology

Chip size: table surface height 30 μ m-35 μ m

Mesa diameter Φ 45 μ m-Φ 50 μ m

Adjacent pipe core space 300 μ m

P ⁺N ^-Junction depth 5 μ m-5.5 μ m

N ^-Layer thickness 24 μ m-25 μ m

N ^-N ^-Junction depth 100 μ m-120 μ m

Glass powder particles degree≤1 μ m, preferred 100nm

Processing step:

1. the silicon device chip that will corrode table top carries out strict chemical cleaning and oven dry.

2. the employing knife coating evenly is coated on the silicon device surface with the superfine glass micro mist (particle diameter≤1 μ m, preferred 100nm) for preparing.

3. under infrared lamp, dry and send into high temperature furnace.

4. (10-10 under low vacuum state ^-1Pa) (470 ℃-550 ℃) degasification 10 minutes in glass degasification humidity province, (600 ℃-630 ℃) preforming is 10 minutes in the glass transition temperature district.750 ℃ of-760 ℃ of compacted unders are 30 minutes in the glass ware forming district.

5. pass furnace annealing.

Embodiment 2: silicon variable capacitance diode glassivation technology

Chip size: table surface height 8 μ m-10 μ m

Mesa diameter Φ 105 μ m-Φ 120 μ m

Adjacent pipe core space 300 μ m

P ⁺N ^-Junction depth 0.6 μ m-0.8 μ m

N ^-Layer thickness 2 μ m-2.5 μ m

N ^-N ^-Junction depth 100 μ m-120 μ m

Glass powder particles degree≤1 μ m, preferred≤100nm

Processing step:

2. employing knife coating, with the superfine glass micro mist for preparing (particle diameter≤1 μ m, preferred≤as 100nm) evenly to be coated on the silicon device surface.

3. under infrared lamp, dry and send into high temperature furnace.

4. (10-10 under low vacuum state ^-1Pa) (470 ℃-550 ℃) degasification 10 minutes in glass degasification humidity province, (600 ℃-630 ℃) preforming is 10 minutes in the glass transition temperature district.(750 ℃-76 0 ℃) compacted under is 30 minutes in the glass ware forming district.

6. the pass stove is lowered the temperature, annealing.

Claims

1. silicon semiconductor device glassivation technology is characterized in that:

A. will prepare the various oxides of passivation glass or corresponding hydroxide or carbonate and make the super fine of particle diameter≤1 μ m as raw material;

B. behind high temperature sintering, the passivation glass that has become is made the glass dust of the super fine of particle diameter≤1 μ m as the passivation device again;

C. following three warm areas in the glassivation thermoforming adopt low vacuum 10-10 ^-1The Pa heat treated:

470 ℃ of-550 ℃ of degasification in glass degasification humidity province 10 minutes;

600 ℃ of-630 ℃ of preforming in glass transition temperature district 10 minutes;

750 ℃ of-760 ℃ of moulding in glass ware forming humidity province 30 minutes.

2. silicon semiconductor device glassivation technology according to claim 1 is characterized in that the various oxides of preparation passivation glass or corresponding hydroxide or carbonate are made the super fine of particle diameter≤100nm as raw material.

3. silicon semiconductor device glassivation technology according to claim 1 is characterized in that behind high temperature sintering, and synthetic passivation glass is made the glass dust of the super fine of particle diameter≤100nm as the passivation device again.