Regulation control method for thin layer epitaxial transition region of heavily doped PH substrate

Abstract

The invention discloses a regulation control method for a thin layer epitaxial transition region of a heavily doped PH substrate, and relates to the technical field of epitaxial layer growth methods. The method comprises the following steps: fixing the temperature and TCS flow of a uniwafer epitaxial growth system during epitaxial growth of a substrate; during the epitaxial growth of the substrate, using a same doping process for CAP layer growth and epitaxial layer growth; and during the epitaxial layer growth, changing a VENT pressure in the uniwafer epitaxial growth system to be greater than or less than a chamber pressure of the system, and adjusting the steepness of a transitional region of the epitaxial layer. According to the method, the epitaxial layer growth rate is influenced by adjusting the matching of a pressure between a VENT pipeline and a cavity without changing the TCS flow, so that the length of the transitional region from the substrate to the epitaxial layer is influenced and controlled, the transitional region is steeper, and the edge resistivity numerical value of the epitaxial layer can be remarkably increased.

Description

technical field

[0001] The invention relates to the technical field of growth methods of epitaxial layers, in particular to a method for regulating and controlling epitaxial transition regions of heavily doped pH substrate thin layers. Background technique

[0002] For the development of new epitaxial materials for low-voltage MOS devices on heavily doped PH substrates, the test results of resistivity (four-probe, 4PP test) are greatly affected by the transition region of the epitaxial layer. Delay, the lower the 4PP test result; for the general epitaxial process, the epitaxial resistivity can be adjusted by adjusting the dopant dose, the epitaxial thickness can be adjusted by the growth rate and growth time, and there is no general method for the epitaxial transition region. Adjustment. With the development of integrated circuits, the market demand for epitaxial materials for large-size low-voltage MOS devices is increasing. At present, the demand for epitaxial materials f...

Examples

Embodiment 1

[0029] The invention discloses a method for regulating and controlling a thin-layer epitaxial transition region of a heavily doped pH substrate, comprising the following steps:

[0030] 1) Fix the temperature and TCS (trichlorosilane) flow rate of the monolithic epitaxial growth system during the epitaxial growth of the substrate.

[0031] 2) During the epitaxial growth of the substrate, the growth of the CAP layer and the growth of the epitaxial layer use the same doping process.

[0032] 3) During the growth of the epitaxial layer, change the VENT (exhaust) pressure in the monolithic epitaxial growth system, so that the VENT pressure is greater than or less than the chamber (cavity) pressure of the system, and adjust the steepness of the epitaxial layer transition zone.

[0033] 4) By adjusting the VENT pressure, the steepness of the epitaxial layer transition zone is changed, and the corresponding epitaxial wafers are respectively analyzed for the extended resistance profil...

Embodiment 2

[0035] The invention discloses a method for regulating and controlling a thin-layer epitaxial transition region of a heavily doped pH substrate, comprising the following steps:

[0036] Using ASME2000 type monolithic epitaxial growth system, such as figure 1 As shown, the infrared lamp array is radiatively heated, the high-purity graphite base is a silicon wafer carrier, and the protective gas is ultra-high-purity H 2 Gas with a purity of over 99.999999%.

[0037] Using 8-inch heavily doped PH substrate, crystal orientation , resistivity range of 0.001-0.0015ohm.cm, supersealing back sealing process;

[0038] Before epitaxial growth, the system is fully removed from the doping treatment. At 1190 ° C, a large flow of HCL gas is introduced at 20 slm / min, and when the residual Si and the residual Si on the base are etched away, the H 2 The flow rate is set to 10slm / min, and when corroding the residual Si on the inner wall of the bell jar, increase the H 2 The flow rate is up t...

technical field

[0001] The invention relates to the technical field of growth methods of epitaxial layers, in particular to a method for regulating and controlling epitaxial transition regions of heavily doped pH substrate thin layers. Background technique

[0002] For the development of new epitaxial materials for low-voltage MOS devices on heavily doped PH substrates, the test results of resistivity (four-probe, 4PP test) are greatly affected by the transition region of the epitaxial layer. Delay, the lower the 4PP test result; for the general epitaxial process, the epitaxial resistivity can be adjusted by adjusting the dopant dose, the epitaxial thickness can be adjusted by the growth rate and growth time, and there is no general method for the epitaxial transition region. Adjustment. With the development of integrated circuits, the market demand for epitaxial materials for large-size low-voltage MOS devices is increasing. At present, the demand for epitaxial materials f...

Examples

Embodiment 1

[0029] The invention discloses a method for regulating and controlling a thin-layer epitaxial transition region of a heavily doped pH substrate, comprising the following steps:

[0030] 1) Fix the temperature and TCS (trichlorosilane) flow rate of the monolithic epitaxial growth system during the epitaxial growth of the substrate.

[0031] 2) During the epitaxial growth of the substrate, the growth of the CAP layer and the growth of the epitaxial layer use the same doping process.

[0032] 3) During the growth of the epitaxial layer, change the VENT (exhaust) pressure in the monolithic epitaxial growth system, so that the VENT pressure is greater than or less than the chamber (cavity) pressure of the system, and adjust the steepness of the epitaxial layer transition zone.

[0033] 4) By adjusting the VENT pressure, the steepness of the epitaxial layer transition zone is changed, and the corresponding epitaxial wafers are respectively analyzed for the extended resistance profil...

Embodiment 2

[0035] The invention discloses a method for regulating and controlling a thin-layer epitaxial transition region of a heavily doped pH substrate, comprising the following steps:

[0036] Using ASME2000 type monolithic epitaxial growth system, such as figure 1 As shown, the infrared lamp array is radiatively heated, the high-purity graphite base is a silicon wafer carrier, and the protective gas is ultra-high-purity H 2 Gas with a purity of over 99.999999%.

[0037] Using 8-inch heavily doped PH substrate, crystal orientation , resistivity range of 0.001-0.0015ohm.cm, supersealing back sealing process;

[0038] Before epitaxial growth, the system is fully removed from the doping treatment. At 1190 ° C, a large flow of HCL gas is introduced at 20 slm / min, and when the residual Si and the residual Si on the base are etched away, the H 2 The flow rate is set to 10slm / min, and when corroding the residual Si on the inner wall of the bell jar, increase the H 2 The flow rate is up t...

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