CN1278654A

CN1278654A - Device transfering technology

Info

Publication number: CN1278654A
Application number: CN 00115500
Authority: CN
Inventors: 王连卫; 刘卫丽; 沈勤我; 林成鲁
Original assignee: Shanghai Institute of Metallurgy of CAS
Current assignee: Shanghai Institute of Optics and Fine Mechanics of CAS
Priority date: 2000-04-27
Filing date: 2000-04-27
Publication date: 2001-01-03
Anticipated expiration: 2020-04-27
Also published as: CN1119830C

Abstract

The technological process for transferring device made on silicon substrate onto special-designal substrate by adopting porous silicon separation process, belonging to the field of microelectronic technology, is characterized by that it utilizes anodization method to prepara porous silicon with layered structure on the monocrystal silicon chip, then make device on the epitaxial layer of porous silicon, and adopting filp-chip sticking technoque to make circuit and special-designal substrate combine together, then utilizing special method to separate substrate silicom from upper layer silicon of made device in porous layer area. The circuit made up by adopting said technology possesses good radiating power and low power consumption, can be used in high-powder device and mobile communication system, and is favourable for combining with MCM technique.

Description

A kind of device transfering technology

The present invention relates to a kind of new device transfer techniques, or rather, the present invention proposes to adopt the porous silicon isolation technics that the electronic device of making on the silicon substrate is transferred to method on the specific substrate, be DTSPS (Device Transferred by Splitting of Porous Silicon), belong to microelectronic.

When making power device and radio circuit, the loss of heat radiation and substrate is the problem that must consider.Because element manufacturing only concentrates on the active layer near the surface, and what the work of device was exerted an influence also only is this active layer, if this part device can be separated from silicon substrate, mount or be bonded on the specific substrate, not only will improve the heat radiation and the loss characteristic of device effectively, for example the silicon radio circuit is transferred on the quartz substrate, find that its power consumption reduces (R.Dekker significantly, IEDN 97-921), this radio circuit that mobile communication is used is very important, and, can dwindle the weight and volume of electronic system effectively, particularly to multichip modules technology (MCM) with significant.

Yet, device transfer research in the past mainly contains two classes, one class is with element manufacturing silicon (Silicon-on-insulator SOI) on insulating barrier, mainly be silicon BESOI on bonding and the thinning back side type insulating barrier, that is to say that this technology at first must be with element manufacturing (R.Dekker on the relatively costly SOI of price, IEDN 97-921), adopt bonding techniques that device is bonded on the specific substrate then, adopt the way of corrosion again, by with SiO ₂Buried regions removes silicon substrate as sacrifice layer, thereby realizes the transfer of device.This transfer techniques also must adopt wet chemical method to remove silicon substrate behind the device back bonding except will adopting the SOI substrate, and this uses for this technology in SMT (surface mounting technology) technology and brings very burden, and may cause technology incompatible.Another kind of is the method that adopts similar Smart-cut SOI, the zone that makes device is injected with hydrogen ion,, annealed by suitable temperature (400～600 ℃) again with device layer and another substrate bonding, thereby make that annotating hydrogen partial separates, thereby reach the purpose that device shifts.The shortcoming of this method is that surface requirements to device surface and bonded substrate is than higher, notes hydrogen also may cause the damage of surface device, and the active layer thickness that can shift mainly determines that by the energy that injects for the implanter of routine, its thickness has only about 1 micron.Surperficial easily breaks and will cause rate of finished products lower, and in addition, 400～600 ℃ treatment temperature may cause shallow junction and the line in the circuit to be destroyed, thereby practical value is limited.

The present invention proposes a kind of novel device transfering technology, it is characterized in that utilizing anodised method on monocrystalline silicon piece, to make porous silicon with hierarchy, epitaxial monocrystalline silicon on porous silicon then, on epitaxial loayer, make circuit, by the way (being surface mount process SMT) that mounts circuit is bonded to specific substrate such as aluminium oxide again, aluminium nitride, a quartzy or other circuit or circuit board, or can support the medium of this thin film circuit, never be only limited to described backing material, reach the purpose that device shifts by substrate is separated along porous silicon layer.

Meaning of the present invention has been to provide a kind of low cost the highly reliable technology of carrying out the high performance device making, for example, the manufacture craft of porous silicon seldom input in general laboratory just can realize, silicon epitaxy process just can be realized on common silicon epitaxy equipment on the porous silicon, and this technology has been close to ripe, the manufacturing process of device is the integrated circuit technology of standard, and paster technique also is the technology of standard.As for separation problem, the dry process that we take, a kind of feasible method is to adopt the Pulse Electric striking, by adding pulse current and make substrate that shock heating realization take place to separate around the silicon chip with between substrate.And the device with similar performance all is will be by BESOI technology usually.

Concrete technological process of the present invention is as follows:

1, utilize anodised method to make the porous silicon with hierarchy on p-or n-Si (100) substrate, its technology is in the HF/ alcohol or the HF/ aqueous solution (V/V is 1: 1), adopts less current density (as 5mA/cm earlier ²) adopt bigger current density as (25mA/cm again ²), on monocrystalline silicon piece, make porous silicon with sandwich construction;

2, implementing upper strata growing epitaxial silicon to suitable thickness on porous silicon can decide according to the device that will make and needs as 2～15 μ m; During epitaxial loayer silicon, temperature is 900-1000 ℃, and reacting gas is SiCl ₄And H ₂

3, utilize the silicon technology of standard to make circuit (as radio circuit or power circuit or other) and carry out circuit package before cut apart cleavage (being scribing);

4, the device that will cut apart is mounted on the specific substrate;

5, adopt the Pulse Electric striking, substrate is separated along porous silicon, reach the purpose that device shifts.But be not only limited to the Pulse Electric striking.

It is pointed out that utilizing the porous epitaxial silicon layer to make device has had years of researches history, for example utilizes porous silicon to make FIPOS (the porous silicon oxidation isolation) technology of SOI.Difference of the present invention is no longer to carry out the oxidation isolation technology and directly carries out the making of device or circuit on epitaxial loayer.And the effect of porous layer is not re-used as oxide isolation regions yet but the Disengagement zone of shifting as device.

Need to prove, recently, a kind ofly be called epitaxial loayer to shift silicon (Eltran SOI) technology on the insulating barrier also be to utilize silicon epitaxy on the porous silicon and with the bonding of another silicon chip and utilize ad hoc approach to realize separating of epitaxial loayer.Different with this method is, the present invention emphasizes directly element manufacturing epitaxial loayer on porous silicon, and the transfer of device to be bonding by attachment process and specific substrate realize.Therefore all be a kind of development from design philosophy and enforcement aspect.

The present invention emphasizes to utilize porous silicon layer to realize the separation of the device that the upper strata silicon epitaxy layer is made, thereby its applicable scope but is not only limited to silicon epitaxy layer, because can realize the epitaxial growth of multiple thin-film materials such as Si, Ge, SiGe, GaAs by porous silicon, thereby can utilize the various corresponding electronic devices of these material, utilize the porous silicon isolation technics can realize the transfer of this class device equally.This will give chipset packing technique and multichip module technology with new intension, i.e. assembling from the Semiconductor substrate that is loaded with circuit carries out the transition to the assembling of the semiconductive thin film that is loaded with circuit, and can realize circuit and pile up with three-dimensional integrated.

Below by embodiment feasibility of the present invention is described.

Embodiment 1

Select p-Si (100), resistivity 0.01～0.03 Ω cm in the HF/ alcoholic solution (v/v is 1/1), adopts two step anodic oxidations, and current density is respectively 5mA/cm ²And 25mA/cm ², extension in the silicon epitaxy stove, reacting gas is SiCl ₄And H ₂950 ℃ of temperature, make n-type silicon epitaxy layer 4 μ m, resistivity 1～3 Ω cm by integrated circuit technology, has made diode array on epitaxial loayer, this array upside-down mounting pasted the substrate that be printed with reading circuit lead-in wire on by the SMT technology these diodes, adopt the pulse electric-shocking method, realized separating of silicon substrate and epitaxial loayer, this diode array can be used for aspects such as photo-detector.

Embodiment 2

Porous silicon and epitaxy technique are the same, but epitaxial thickness is 12 μ m, the circuit of making is a kind of ambipolar emitter follower circuit (automobile is used), the circuit upside-down mounting is sticked on the ceramic substrate of thick film circuit by the SMT technology, carry out separating technology again and remove substrate, this circuit has extraordinary heat dispersion.

Claims

1, a kind of device transfering technology is characterized in that

(1) utilize anode oxidation method on monocrystalline silicon, to make porous silicon with hierarchy;

(2) on porous silicon, realize the upper strata growing epitaxial silicon, on epitaxial loayer, make circuit, and carry out the cleavage of cutting apart before the circuit package;

(3) adopt mount technology with the circuit back bonding on particular substrate;

(4) substrate silicon is separated along porous silicon layer with the upper strata silicon of making device.

2, according to the described device transfering technology of claim 1, the porous silicon that it is characterized in that described hierarchy, make on p-or n-Si (100) substrate, its technology is to adopt less current density in the HF/ alcohol or the HF/ aqueous solution earlier, adopts bigger current density again.

3, according to claim 1 and 2 described device transfering technologies, it is characterized in that with epitaxy single-crystal silicon thickness on porous silicon be 2～15 μ m, specifically decide according to the requirement of element manufacturing.

4, according to the described device transfering technology of claim 1, it is characterized in that the device technology of being carried out is the silicon technology of standard on the epitaxial monocrystalline silicon of porous silicon, comprise CMOS technology, bipolar process.

5, according to the described device transfering technology of claim 1, what it is characterized in that device that on porous silicon epitaxial monocrystalline silicon is made utilizes SMT or similar techniques, with circuit and specific substrate stickup.

6,, it is characterized in that it is to adopt the Pulse Electric striking that described substrate separates along porous silicon, but be not only limited to this method according to the described device transfering technology of claim 1.

7,, it is characterized in that device or circuit that Si, SiGe, Ge, GaAs film that the device that is transferred or circuit can be extension on porous silicon are made according to the described device transfering technology of claim l.

8,, it is characterized in that described substrate can be Al according to the described device transfering technology of claim 1 ₂O ₃, AlN, quartz substrate, also can be an other circuit or circuit board, or can support the medium of this thin film circuit, but never be only limited to described here and backing material.

9,, it is characterized in that to adopt the method to realize the integrated of piling up of circuit and three-dimensional according to the described device transfering technology of claim 1.