公开(公告)号：DE3786851T2

公开(公告)日：1994-03-17

申请号：DE3786851

申请日：1987-05-05

Applicant: IBM

Inventor： BENNETT REID STUART ,  EPHRATH LINDA MERO ,  SCHWARTZ GERALDINE COGIN ,  SELWYN GARY STEWART

IPC: H01L21/302 ,  C23F1/00 ,  G01N21/64 ,  H01J37/32 ,  H01L21/306 ,  H01L21/3065 ,  H01L21/311 ,  H01L21/3213 ,  C23F4/00

Abstract: Laser induced fluorescence is utilized to detect the reactive ion etch-through of a given layer in a wafer by detecting a large change in the concentration of a wafer selected minor species from the wafer in the etching plasma. This selected minor species must be present in a significantly different concentration in the etched given layer compared to any of the other layers in the wafer in order to provide a proper endpoint detection. In one embodiment, when the large change in the selected minor species concentration is detected, then the RF electrodes for the reactor are de-energized.

公开(公告)号：DE3786851D1

公开(公告)日：1993-09-09

申请号：DE3786851

申请日：1987-05-05

Applicant: IBM

Inventor： BENNETT REID STUART ,  EPHRATH LINDA MERO ,  SCHWARTZ GERALDINE COGIN ,  SELWYN GARY STEWART

IPC: H01L21/302 ,  C23F1/00 ,  G01N21/64 ,  H01J37/32 ,  H01L21/306 ,  H01L21/3065 ,  H01L21/311 ,  H01L21/3213 ,  C23F4/00

Abstract: Laser induced fluorescence is utilized to detect the reactive ion etch-through of a given layer in a wafer by detecting a large change in the concentration of a wafer selected minor species from the wafer in the etching plasma. This selected minor species must be present in a significantly different concentration in the etched given layer compared to any of the other layers in the wafer in order to provide a proper endpoint detection. In one embodiment, when the large change in the selected minor species concentration is detected, then the RF electrodes for the reactor are de-energized.

公开(公告)号：DE3879418D1

公开(公告)日：1993-04-22

申请号：DE3879418

申请日：1988-10-25

Applicant: IBM

Inventor： KELLER JOHN HOWARD ,  SELWYN GARY STEWART ,  SINGH JOYTHI

IPC: H01L21/302 ,  H01J37/32 ,  H01L21/3065

Abstract: A plasma processing apparatus and process endpoint detection method comprising a plasma chamber for processing an item that has a first portion of a first material and a second portion of a second material, with the first and second materials having different work functions, and means for generating a plasma in the plasma chamber, with the plasma generating means including at least a pair of RF-power electrodes with one of them being excited by an RF excitation frequency. The apparatus further includes means for generating and ejecting electrons from said second material only when the second material is exposed to the plasma, and means for increasing the energies of these generated electrons and accelerating these electrons into the etching plasma with sufficient energy to generate secondary electrons in the plasma. The apparatus further includes means for receiving a plasma discharge voltage signal, means for filtering the discharge electrical voltage signal to remove the RF excitation frequency and any DC components therein, and means for amplifying the natural frequencies of excitation and decay of the plasma discharge voltage perturbation signal, to thereby detect the processing endpoint. In a preferred embodiment, the electron energy increasing and accelerating means comprises means for generating an electrode voltage sheath, and means for generating the electrons within this voltage sheath to thereby accelerate the electrons into the plasma. The electron generating means comprises means for directing a beam of photons in a selected energy range onto the item to be processed, which energy range is not sufficient to eject photoelectrons from the first material, but is high enough to generate photoelectrons from areas of exposed second material.

公开(公告)号：DE3879418T2

公开(公告)日：1993-09-23

申请号：DE3879418

申请日：1988-10-25

Applicant: IBM

Inventor： KELLER JOHN HOWARD ,  SELWYN GARY STEWART ,  SINGH JOYTHI

IPC: H01L21/302 ,  H01J37/32 ,  H01L21/3065

Abstract: A plasma processing apparatus and process endpoint detection method comprising a plasma chamber for processing an item that has a first portion of a first material and a second portion of a second material, with the first and second materials having different work functions, and means for generating a plasma in the plasma chamber, with the plasma generating means including at least a pair of RF-power electrodes with one of them being excited by an RF excitation frequency. The apparatus further includes means for generating and ejecting electrons from said second material only when the second material is exposed to the plasma, and means for increasing the energies of these generated electrons and accelerating these electrons into the etching plasma with sufficient energy to generate secondary electrons in the plasma. The apparatus further includes means for receiving a plasma discharge voltage signal, means for filtering the discharge electrical voltage signal to remove the RF excitation frequency and any DC components therein, and means for amplifying the natural frequencies of excitation and decay of the plasma discharge voltage perturbation signal, to thereby detect the processing endpoint. In a preferred embodiment, the electron energy increasing and accelerating means comprises means for generating an electrode voltage sheath, and means for generating the electrons within this voltage sheath to thereby accelerate the electrons into the plasma. The electron generating means comprises means for directing a beam of photons in a selected energy range onto the item to be processed, which energy range is not sufficient to eject photoelectrons from the first material, but is high enough to generate photoelectrons from areas of exposed second material.

公开(公告)号：BR8806481A

公开(公告)日：1989-08-22

申请号：BR8806481

申请日：1988-12-08

Applicant: IBM

Inventor： KELLER JOHN HOWARD ,  SELWYN GARY STEWART ,  SINGH JOYTHI

IPC: H01L21/302 ,  H01J37/32 ,  H01L21/3065 ,  H05H1/24

Abstract: A plasma processing apparatus and process endpoint detection method comprising a plasma chamber for processing an item that has a first portion of a first material and a second portion of a second material, with the first and second materials having different work functions, and means for generating a plasma in the plasma chamber, with the plasma generating means including at least a pair of RF-power electrodes with one of them being excited by an RF excitation frequency. The apparatus further includes means for generating and ejecting electrons from said second material only when the second material is exposed to the plasma, and means for increasing the energies of these generated electrons and accelerating these electrons into the etching plasma with sufficient energy to generate secondary electrons in the plasma. The apparatus further includes means for receiving a plasma discharge voltage signal, means for filtering the discharge electrical voltage signal to remove the RF excitation frequency and any DC components therein, and means for amplifying the natural frequencies of excitation and decay of the plasma discharge voltage perturbation signal, to thereby detect the processing endpoint. In a preferred embodiment, the electron energy increasing and accelerating means comprises means for generating an electrode voltage sheath, and means for generating the electrons within this voltage sheath to thereby accelerate the electrons into the plasma. The electron generating means comprises means for directing a beam of photons in a selected energy range onto the item to be processed, which energy range is not sufficient to eject photoelectrons from the first material, but is high enough to generate photoelectrons from areas of exposed second material.