RU2586009C1 - Method of making semiconductor structure - Google Patents

Abstract

FIELD: instrument making.

SUBSTANCE: invention relates to technology for production of semiconductor devices, particularly to production of semiconductor structures with low density of defects. In method of making semiconductor structure, growing of epitaxial layer Si_1-xGe_x is performed at a rate of 10 nm/min, at pressure 0.133 Pa, temperature of 750 °C, SiH₄ consumption of 10 cm³/min and ratio of concentrations of mixture GeH₄:SiH₄ = 3-6 %.

EFFECT: technical result is reduction of density of defects, providing processibility, improving parameters, high reliability and percentage yield.

1 cl, 1 tbl

Description

The invention relates to the field of production technology of semiconductor devices, in particular to a technology for the manufacture of semiconductor structures with a low density of defects.

A known method of growing epitaxial layers of GaAs [US Pat. 5068695 USA, MKI H01L 29/161] with a low dislocation density. A GaAs substrate with a high dislocation density undergoes implantation of boron B ions with an energy of 350 keV. Upon subsequent rapid annealing with a protective layer at 900 ° C for 25 s, a recrystallized Ga _1-x B _x As layer with a reduced dislocation density is formed. A GaAs epitaxial layer is then grown on this layer. In such structures formed under the influence of high energies, leaks are formed that worsen the parameters of the devices.

The known method [Pat. 5091767 USA, MKI H01L 29/04] fabrication of a GeSi / Si structure with a matched crystal lattice and low dislocation density. At the boundary of the GeSi layer and the Si substrate, a hidden SiO _{2 region} 200 nm thick is formed, which serves as a drain for dislocations moving from the upper GeSi layer.

The disadvantages of this method are:

- increased density of defects in the surface layer of Si;

- significant leakage currents,

- low manufacturability.

The problem solved by the invention: reducing the density of defects, ensuring manufacturability, improving parameters, improving reliability and increasing the percentage of yield.

The problem is solved by growing layers of Si _1-x Ge _x at a flow rate of SiH ₄ - 10 cm ³ / min, with ratios of GeH ₄ : SiH ₄ = 3-6%; pressure 0.133 Pa, at a temperature of 750 ° C.

The technology of the method is as follows: Si _1-x Ge _{x was} grown on a silicon substrate Si with an orientation of (100) by the PFC method at a pressure of 1.33 Pa and a temperature of 750 ° C. For deposition, a reactor with radiation heating and a Si-coated graphite pedestal, on which the plates were placed, was used. The plasma was created using an RF generator operating at a frequency of 13.56 MHz. A constant negative bias was applied to the pedestal in order to accelerate the ions during the sputtering process. After purification with argon: the flow of Ar, the displacement of the pedestal, the RF power were turned off, and SiH _{4 was} fed into the reactor to grow an epitaxial Si layer with a thickness of 240-300 nm. The Si _1-x Ge _x layer was grown after stopping the supply of SiH ₄ and purging for 30 s from a mixture of SiH ₄ and GeH ₄ at a pressure of 0.133 Pa. Cultivation layers Si _1-x Ge _x was produced at flow rates of SiH ₄ - 10 cm ³ / min and ratios GeH _4: SiH ₄ 3-6% at 10 nm / min.

According to the proposed method, semiconductor structures were manufactured and investigated. The processing results are presented in the table.

Experimental studies have shown that the yield of semiconductor structures on a batch of wafers formed in the optimal mode increased by 16.4%.

EFFECT: reduced density of defects, ensuring manufacturability, improved parameters, increased reliability and increased percentage of yield of suitable structures.

The stability of the parameters over the entire operating temperature range was normal and consistent with the requirements.

The proposed method for the manufacture of semiconductor structures by growing layers of Si _1-x Ge _x at a speed of 10 nm / min, at a flow rate of SiH ₄ - 10 cm ³ / min, a pressure of 0.133 Pa, a temperature of 750 ° C, with a mixture ratio of GeH ₄ : SiH ₄ = 3-6%, allows to increase the percentage of yield and improve their reliability.

Claims (1)

A method of manufacturing a semiconductor structure, including a silicon substrate, the processes of growing the epitaxial layer, characterized in that the growing epitaxial layer of Si _1-x Ge _{x is} produced at a speed of 10 nm / min, at a pressure of 0.133 Pa, a temperature of 750 ° C, a flow rate of SiH _{4 of} 10 cm ³ / min and the ratio of the concentration of the mixture of GeH ₄ : SiH ₄ = 3-6%.