<PAGE>
                                                                    Exhibit 4.16

                        DATED THE 30TH DAY OF JUNE, 1999

                         ASM PACIFIC TECHNOLOGY LIMITED

              THE COMPANIES WHOSE NAMES ARE SET OUT IN THE SCHEDULE

                                       and

                    A.H. DEL PRADO and LAM SEE PONG, PATRICK



                ------------------------------------------------
                                SUPPLEMENTAL DEED
                                   RELATING TO
                       THE EMPLOYEE SHARE INCENTIVE SCHEME
                                       OF
                         ASM PACIFIC TECHNOLOGY LIMITED

               --------------------------------------------------








                              JENNIFER CHEUNG & CO.
                                   Solicitors
                                    Hong Kong
                                  (JC/0020/99)
<PAGE>
THIS SUPPLEMENTAL DEED is made the 30th day of June, 1999

BETWEEN   :

(1)      ASM PACIFIC TECHNOLOGY LIMITED whose registered office is at Caledonian
         House, Grand Cayman, Cayman Islands, British West Indies (the
         "Company");

(2)      THE COMPANIES whose names are set out in the Schedule; and

(3)      A.H. DEL PRADO of Jan Steenlan 9,3723 BS Bilthoven, the Netherlands and
         Lam See Pong, Patrick of Princess Terrace, 11th Floor, Block A, 21 Man
         Fuk Road, Kowloon, Hong Kong (the "First Trustees").

WHEREAS:

(A)      The Company, ASM Asia Limited, ASM Assembly Automation Limited,
         Advanced Semiconductor Materials (Overseas) Limited (which was
         dissolved on 21st December, 1993), ASM Assembly Materials Limited and
         the First Trustees executed a deed dated 23rd March, 1990 relating to
         the establishment of a share incentive scheme for the provision by the
         Company and other Participating Companies of funds for the subscription
         or purchase by the Trustees of Shares (the "Deed"). The other companies
         named in the Schedule hereto are Participating Companies joining the
         Scheme subsequent to the date of the Deed.

(B)      By a resolution of the shareholders of the Company passed on 25th June,
         1999, amendments to the Rules were approved.

NOW THIS SUPPLEMENTAL DEED WITNESSETH as follows:

1.       Definitions

         Words and expressions defined in the Deed and the rules set out in
         Schedule 1 to the Deed shall, unless the context otherwise requires,
         have the same meanings in this Supplemental Deed, including the
         recitals hereto.

2.       Alterations to the Scheme

2.1      The parties hereto agree that the Rules shall be amended as follows:

         (a)      The existing provisions of Rule 2.1.1 be deleted and be
                  replaced by the following:

                  "2.1.1.  what percentage of the consolidated profits (before
                           tax and extraordinary items) of the Group in respect
                           of the said previous year shall be paid to the
                           trustees to be held by them upon the terms of the
                           Scheme, provided that such shall not exceed 2
                           percent."

         (b)      The existing provisions of Rule 4.1 be deleted and be replaced
                  by the following with effect from 23rd March, 2000:

                                      -1-
<PAGE>
                  "4.1     The maximum aggregate number of Shares which may be
                           subscribed for or purchased by the Trustees pursuant
                           to the Scheme after 23rd March, 2000 shall not exceed
                           5 percent, of the issued share capital of the Company
                           from time to time, excluding any Shares acquired
                           pursuant to the Scheme since 23rd March, 1990,
                           provided that not more than 2 percentage, of the
                           number of Shares in issue at the commencement of any
                           year (excluding any Shares subscribed for or
                           purchased then under the Scheme since 23rd March,
                           1990) may be subscribed for or purchased pursuant to
                           the Scheme in that year."

         (c)      Rule 8.2 of the Scheme be amended to the effect that the
                  Scheme shall only terminate on 23rd March, 2010 and that the
                  figure "10th" appearing in such Rule be deleted and be
                  replaced by the figure "20th".

2.2      Save as amended aforementioned, all the terms and conditions contained
         in the Scheme and the Deed shall remain in full force and effect.

3.       Governing Law

         This Supplemental Deed shall be governed by and construed in accordance
         with the laws of Hong Kong.

IN WITNESS whereof these presents have been entered into the day and year first
above written.

THE COMMON SEAL of ASM PACIFIC      )
TECHNOLOGY LIMITED was              )
hereunto affixed in the             )
presence of:                        )




/s/  Arthur H. del Prado                    /s/  Patrick Lam See Pong
------------------------------------        ------------------------------------
A.H. Del Prado                              Lam See Pong, Patrick
Director                                    Director



                                      -2-
<PAGE>
THE COMMON SEAL of ASM ASIA         )
LIMITED was hereunto affixed        )
in the presence of:                 )




/s/  Arthur H. del Prado                    /s/  Patrick Lam See Pong
------------------------------------        ------------------------------------
A.H. Del Prado                              Lam See Pong, Patrick
Director                                    Director




THE COMMON SEAL of ASM              )
ASSEMBLY AUTOMATION LIMITED         )
was hereunto affixed in the         )
presence of:                        )




/s/  Arthur H. del Prado                    /s/  Patrick Lam See Pong
------------------------------------        ------------------------------------
A.H. Del Prado                              Lam See Pong, Patrick
Director                                    Director




THE COMMON SEAL of ASM              )
ASSEMBLY MATERIALS LIMITED          )
was hereunto affixed in the         )
presence of:                        )




/s/  Arthur H. del Prado                    /s/  Patrick Lam See Pong
------------------------------------        ------------------------------------
A.H. Del Prado                              Lam See Pong, Patrick
Director                                    Director




                                      -3-
<PAGE>
THE COMMON SEAL of ASM              )
TECHNOLOGY SINGAPORE PTE            )
LIMITED was hereunto affixed        )
in the presence of:                 )




/s/  Arthur H. del Prado                    /s/  Patrick Lam See Pong
------------------------------------        ------------------------------------
A.H. Del Prado                              Lam See Pong, Patrick
Director                                    Director




THE COMMON SEAL of CAPITAL          )
EQUIPMENT DISTRIBUTION LIMITED      )
was hereunto affixed in the         )
presence of:                        )




/s/  Patrick Lam See Pong                   /s/  Alan Fung Shu Kan
------------------------------------        ------------------------------------
Lam See Pong, Patrick                       Fung Shu Kan, Alan
Director                                    Director

SIGNED SEALED AND DELIVERED by      )
A.H. DEL PRADO in the presence      )
of:                                 )


/s/  Trudy Veldhuisen                       /s/  Arthur H. del Prado
------------------------------------
Trudy Veldhuisen


                                      -4-
<PAGE>
SIGNED SEALED AND DELIVERED by      )
LAM SEE PONG, PATRICK in the        )
presence of:                        )


/s/  Amy Wong Yee Man                       /s/  Patrick Lam See Pong
------------------------------------
Wong Yee Man, Amy


                                      -5-
<PAGE>
                                    SCHEDULE

                         PARTICIPATING NEW SUBSIDIARIES

ASM ASIA LIMITED

ASM ASSEMBLY AUTOMATION LIMITED

ASM ASSEMBLY MATERIALS LIMITED

ASM TECHNOLOGY SINGAPORE PTE LIMITED

CAPITAL EQUIPMENT DISTRIBUTION LIMITED



                                      -6-