RU2580181C1 - Method of making semiconductor device - Google Patents

Abstract

FIELD: instrument making.

SUBSTANCE: invention relates to technology for production of semiconductor devices, particularly to production of bipolar transistors with low leakage currents. In method of making semiconductor device base region is formed by boron diffusion from anodic oxide films in silicon at temperature 1473 K for 90 minutes in a stream of nitrogen 1.2·10^-2 l/s.

EFFECT: invention ensures reduction of leakage current values, high technological effectiveness, improved parameters of devices, higher reliability and percentage yield.

1 cl, 1 tbl

Description

The invention relates to the field of production technology of semiconductor devices, in particular to the manufacturing technology of bipolar transistors with reduced leakage currents.

A known method of manufacturing a semiconductor device [US patent 5104829, MKI H01L 21/02] the formation of the MOS field effect transistor and bipolar transistor for BiKMOS IC. In the SiO ₂ / Si ₃ N ₄ / SiO ₂ layers covering the Si substrate, two windows are etched and two n + pockets are created by As diffusion. A thicker layer of SiO _{2 is} grown on n + pockets and boron diffusion is carried out in the window between them to form a p + pocket. Then, the SiO ₂ sites are removed and the entire structure is covered with an epitaxial n-layer. Then, above the first n + pocket, the p + pocket and the second n + pocket, respectively, form p MOS - field-effect transistor, n MOS - field-effect transistor and n-pn bipolar transistor. In such semiconductor devices, due to the low manufacturability of the formation of insulating layers, a large number of defects are formed that worsen the parameters of the structures

A known method of manufacturing a semiconductor device [application 2110937, Japan, MKI H01L 21/331] the formation of complementary bipolar transistor structures with isolation pn junction. To suppress dislocation sockets and, consequently, current leaks, hidden n + layers are formed with different dopant concentrations. First, one layer of silicate glass is deposited on open windows in the oxide to dope the hidden n + layers, then this glass layer is removed, oxide is deposited and the windows are opened under the hidden layers for n-pn bipolar transistors, a second glass layer is deposited and an additional impurity is plugged into open windows. As a result, hidden n + type layers with different degrees of doping and different thicknesses are obtained that perform certain functions for both types of bipolar transistors.

The disadvantages of the method are: increased values of leakage currents; low manufacturability; deterioration of electrical parameters.

The problem solved by the invention: reducing leakage currents, ensuring manufacturability, improving instrument parameters, increasing reliability and increasing yield.

The problem is solved by creating the base region of a semiconductor device by diffusing boron from anodic oxide films in silicon at a temperature of 1473 K for 90 minutes in a nitrogen stream of 1.2 · 10 ^-2 l / s.

The technology of the method is as follows. On p-type silicon wafers with a resistivity of 10 Ω cm, (111) orientation an n-type epitaxial layer was formed, insulating regions and a base region were formed. The creation of the base region of a semiconductor device was carried out by diffusion of boron from anodic oxide films in silicon at a temperature of 1473 K for 90 min in a nitrogen stream of 1.2 · 10 ^-2 l / s. The formation of boron-containing anode oxide films was carried out on a setup with a vacuum suction cup in a borate electrolyte with a nitrate conductive additive with a mass fraction of H ₃ BO _{3 of} 10% at an electrolyte temperature of 293 K and a constant current density of 100 A / m ² , and then up to a ten-fold decrease in current density. Then the emitter and collector regions were formed using standard technology.

According to the proposed method, devices were manufactured and investigated. The processing results are presented in table 1.

Experimental studies have shown that the yield of suitable semiconductor devices in a batch of wafers formed in the optimal mode increased by 13.5%.

Effect: reduction of leakage currents, ensuring manufacturability, improving the parameters of structures, increasing reliability and increasing the percentage of yield.

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

The proposed method for manufacturing a semiconductor device by creating a base region of a transistor by diffusion of boron from anodic oxide films in silicon at a temperature of 1473 K for 90 minutes in a nitrogen stream of 1.2 × 10 ^-2 l / s allows to increase the percentage of suitable devices and improve their reliability.

Claims (1)

A method of manufacturing a semiconductor device, including a silicon substrate, an epitaxial layer, doping processes, characterized in that the base region is created by the formation of boron-containing anode oxide films in a borate electrolyte with a nitrate conductive additive with a mass fraction of H ₃ BO _{3 of} 10% at an electrolyte temperature of 293 K and a constant current density of 100 a / m ² and then up to a tenfold decrease in current density, followed by diffusion of boron from the anodic oxide film into the silicon at a temperature of 1473 K for 90 min in a homo e nitrogen of 1.2 · 10 ^-2 l / s.